Comparing Quantities Class 8 MCQ Questions

Comparing Quantities Class 8 MCQ Questions with Answers Maths are covered in this Article. Comparing Quantities Class 8 MCQs Test contains 42 questions. Answers to MCQs on Comparing Quantities Class 8 Maths are available at the end of the last question. These MCQ have been made for Class 8 students to help check the concept you have learnt from detailed classroom sessions and application of your knowledge.

Board CBSE
Textbook Maths (NCERT)
Class Class 8
Chapter Chapter 8 Comparing Quantities

Comparing Quantities Class 8 MCQ Questions with Answers

1.Convert 58 % into a Fraction?

(a) 50/29

(b) 29/53

(c) 29/50

Answer

Answer: (c) 29/50

Explanation: In order to convert a Percentage into a Fraction, we divide the Percentage by 100, and remove the sign of Percentage (%).

We have,

58 % = 58/100

On Simplifying, 58/100

HCF of 58 and 100 is 2

Divide both 58 and 100 by their HCF

(58÷2)/(100÷2) = 29/50


 

2. Convert 12 % into a decimal Fraction.

(a) 1.2

(b) 0.12

(c) 0.012

Answer

Answer: (b) 0.12

Explanation: In order to convert given Percentage into into decimal we have to perform the following steps:

Step 1 – Convert the Percentage into Fraction, by dividing the given Percentage by 100

i.e., 12 % = 12/100

Step 2 – Convert the Fraction obtained at Step 1, into a Decimal form , by dividing numerator by Denominator

i.e., 12/100 = 0.12

Hence, 12 % = 0.12


 

3.Convert 13 : 325 into a Percentage.

(a) 4 %

(b) 8 %

(c) 12 %

Answer

Answer: (a) 4 %

Explanation: To convert the given ratio into Percentage we have to follow following steps:

Step 1 – Convert the ratio into Fraction

13 : 325 = 13/325

Step 2 – Multiply the Fraction by 100 and put the Percentage sign to the result (%)

( (13/325) x 100 ) %

On solving the given Fraction, we get,

= 4 %


 

4.Convert (32/100) into Percentage

(a) 32 %

(b) 320 %

(c) 3.2 %

Answer

Answer: (a) 32 %

Explanation: To convert a Fraction into Percentage, we need to multiply the Fraction by 100, and assign the Percentage (%) sign to it.

that is, ( (32/100)x 100 ) % = 32 %





5.Express 36 % as a ratio.

(a) 25 : 9

(b) 9 : 25

Answer

Answer: (b) 9 : 25

Explanation: In order to express a Percentage as a ratio, we need to write

First term / Second term = Given Percentage / 100 = 36/100

On Simplifying, 36/100

HCF of 36 and 100 is 4

Divide both 36 and 100 by their HCF

(36÷4)/(100÷4) = 9/25 = 9 : 25


 

6.If 74 % of a number is 1665, find the number?

(a) 2250

(b) 1125

(c) 2500

Answer

Answer: (a) 2250

Explanation: We can form a linear equation to express the given statement and then arrive at the number

Let the required number be x

We are given that

74 % of x is 1665

or in other words

(74/100) x x = 1665

On cross multiplication, we get

x = (1665×100)/74

x = 2250

Hence, the number is 2250


 

Comparing Quantities Class 8 MCQ Questions with Answers

7.What percent of 90 litres is 54 litres ?

(a) 65 %

(b) 70 %

(c) 60 %

Answer

Answer: (c) 60 %

Explanation: Let a % of 90 litres = 54 litres

Step 1 – Convert the Percentage into Fraction

i.e., a % = a/100

Step 2 – Multiply the Fraction with given quantity.

i.e., ( (a×90)/100 ) litres = ( 54 ) litres

(a×90)/100 = 54

a = (54×100)/90

a = 60

Hence, 54 litres is 60 % of 90 litres


 

8.What percent of 600 m is 300 m?

(a) 50 %

(b) 60 %

(c) 55 %

Answer

Answer: (a) 50 %

Explanation: Let a % of 600 m = 300 m

Step 1 – Convert the Percentage into Fraction

i.e., a % = a/100

Step 2 – Multiply the Fraction with given quantity.

i.e., ((a×600)/100 ) m = ( 300 ) m

(a×600)/100 = 300

a = (300×100)/600

a = 50

Hence, 300 m is 50 % of 600 m


 

9.What percent of 20 kg is 16 kg ?

(a) 90 %

(b) 80 %

(c) 85 %

Answer

Answer: (b) 80 %

Explanation: Let a % of 20 kg = 16 kg

Step 1 – Convert the Percentage into Fraction

i.e., a % = a100

Step 2 – Multiply the Fraction with given quantity.

i.e., ( (a×20)/100 ) kg = ( 16 ) kg

(a×20)/100 = 16

a = (16×100)/20

a = 80

Hence, 16 kg is 80 % of 20 kg





10.A number is increased by 40 % and then decreased by 15 %. The net increase or decrease percentage is?

(a) Increased by 25 %

(b) Decreased by 19 %

(c) Increased by 19 %

(d) Decreased by 25 %

Answer

Answer: (c) Increased by 19 %

Explanation: We can form a linear equation to express the given statement and then arrive at the number

Let the required number be “a”

Step I:

If the number is increased by 40 % it would be equal to ( Given Number + 40 % of Given Number )

= ( a + (40a/100) )

= ( 1 + (40/100) ) a

= (( 100+40)/100 ) a

= 140a/100

Step II:

If the number at Step 1 is decreased by 15 % it would be equal to ( Increased Number – 15 % of Increased Number )

= ( (140a/100) – (15/100) x (140a/100) )

= ( (140a/100) – (2100a/10000) )

= ( (14000−2100)/10000 ) a

= 11900a/10000

= 119a/100

Net Increase = ( (119a/100) – a )

= ( (119a−100a)/100 )

= 19a/100

Net Increase Percentage = ( (19a/100) x (1/a) x 100 )

= 19 %

Hence, Net Increase Percentage is = 19 %


 

11.A number when decreased by 63 % gives 222. The number is?

(a) 595

(b) 600

(c) 610

Answer

Answer: (b) 600

Explanation: Here we take the help of linear equation. First we will form the equation.

Let the number be ‘a’

63 % of ‘a’ = (63/100)a

Since, the equation is:

a -(63/100)a = 222

Taking 100 as LCM on LHS

(100a−63a)/100 = 222

(37/100)a = 222

a = (222×100)/37

a = 600

Hence, the number is 600


 

12.A number, when increased by 125% gives 1125. The number is?

(a) 490

(b) 500

(c) 510

Answer

Answer: (b) 500

Explanation: The problem can be solved using linear equation.

Let the number be ‘a’

125% of a = (125/100)a

We are given that, a + (125/100)a = 1125

Taking 100 as LCM on LHS

(100a+125a)/100 = 1125

(225/100)a = 1125

a = (1125×100)/225

a = 500
Hence, the number is 500


 

Comparing Quantities Class 8 MCQ Questions with Answers

13.Tania spends 12 % of her Salary and saves the rest If she saves ₹ 12760 per month,

(a) ₹ 15500

(b) ₹12500

(c) ₹14500

Answer

Answer: (c) ₹14500

Explanation: Let Tania’s monthly salary be ₹ a

Expenditure = 12 % of her Salary

Expenditure = 12 % of ₹ a

= (12/100) x ₹ a

= ₹ (12a/100)

Savings = Salary – Expenditure = 100 % – 12 % = 88 %

Savings = ₹ ( a – (12a/100))

= ₹ ( (100a−12a)/100 )

= ₹ (88a/100)

Given,

Savings = 12760 = 88 % of a

₹ 12760 = ₹ (88a/100)

a = ₹ ( (12760×100)/88 )

a = ₹ 14500

Tania’s monthly salary is ₹ 14500





14. 8 Oranges are bought for ₹ 80 and sold 3 oranges for ₹ 36 . Find his gain or loss percent ?

(a) Gain % = 20 %

(b) Gain % = 30 %

(c) Loss % = 15 %

Answer

Answer: (a) Gain % = 20 %

Explanation: C.P of 8 Oranges = ₹ 80

C.P of 1 Orange = ₹ 80/8 = 10

S.P of 3 Oranges = ₹ 36

S.P of 1 Orange = ₹ 36/3 = 12

On comparing C.P and S.P

10 , 12

10 < 12

Since,

C.P < S.P

Clearly, some gain has been earned

Gain = S.P – C.P

= 12 – 10

Gain = ₹ 2

Further

Gain% = ( (Gain/C.P) x 100 ) %

= ( (2/10) x 100 ) %

Gain% = 20 %


 

15.A man bought an article for ₹ 8000 and sold it for ₹ 10000 . Find the Gain% earned by him ?

(a) 11 %

(b) 35 %

(c) 25 %

Answer

Answer: (c) 25 %

Explanation: C.P of an article = ₹ 8000

S.P of an article = ₹ 10000

Since,

S.P > C.P

So,

some profit has been earned

We know that,

Gain = S.P – C.P

= 10000 – 8000

= ₹ 2000

Further

Gain% = ( (Gain/C.P) x 100 ) %

= ( (2000/8000) x 100 ) %

Gain% = 25 %


 

16.Find Gain% if C.P = ₹ 4600 and S.P = ₹ 9430 ?

(a) Gain% = 103 %

(b) Gain% = 105 %

(c) Gain% = 100 %

Answer

Answer: (b) Gain% = 105 %

Explanation: C.P = ₹ 4600

S.P = ₹ 9430

Cost Price (CP) – Price at which an Article is purchased.

Selling Price (SP) – Price at which an Article is sold.

Gain – Where the Selling Price is greater than the Cost Price, the difference between the SP and CP is the gain

Clearly,

S.P > C.P

It means that a profit has been earned on such a Sale

Since,

Gain = S.P – C.P

Gain = 9430 – 4600

= ₹ 4830

Now,

we have to calculate Profit percentage

Gain % = (Gain(in₹)×100)/C.P %

Gain % = ( (4830/4600) X 100 ) %

= 105 %

So, the gain % is 105 %


 

17.Krishna purchased a pair of shoes for ₹ 4000 . He paid ₹ 500 as transportation charges . Thereafter, he sold to it Mukesh for ₹ 5175 . Find the gain percentage of Krishna ?

(a) 15 %

(b) 23 %

(c) 10 %

Answer

Answer: (a) 15 %

Explanation: C.P of pair of shoes = ₹ 4000

Transportation charges = ₹ 500

Transportation charge is an overhead expenses and increases the cost of the pair of shoes

Overhead expenses = Overhead expenses are certain other expenses incurred by the Seller, and hence are added to his cost price.

Therefore,

Total Cost Price = Cost price + Transportation charges

Total Cost Price = 4000 + 500

= ₹ 4500

S.P of pair of shoes = ₹ 5175

Clearly,

S.P > C.P

This indicates that some profit has been earned

Therefore,

Gain = S.P – Total Cost Price

= 5175 – 4500

= ₹ 675

Since,

Gain% = ( (Gain/C.P) x 100 ) %

= ( (675/4500) x 100 ) %

= 15 %

Hence, Gain% = 15 %


 

18. If the cost price of an article is ₹ 5500 and selling price of the article is ₹ 4400 . Find the loss% ?

(a) 17 %

(b) 20 %

(c) 23 %

Answer

Answer: (b) 20 %

Explanation: C.P of an article = ₹ 5500

S.P of an article = ₹ 4400

Since,

C.P > S.P

It means that

Some loss has been incurred

We know that,

Loss = C.P – S.P

= 5500 – 4400

= ₹ 1100

Further

Loss% = ( (Loss/C.P.) x 100 ) %

Loss% = ( (1100/5500) x 100 ) %

= 20 %


 

Comparing Quantities Class 8 MCQ Questions with Answers

19.If the cost price of an article is ₹ 7200 and selling price of the article is ₹ 5400 . Find the loss% ?

(a) 17 %

(b) 20 %

(c) 25 %

Answer

Answer: (c) 25 %

Explanation: C.P of an article = ₹ 7200

S.P of an article = ₹ 5400

Since,

C.P > S.P

It means that

Some loss has been incurred

We know that,

Loss = C.P – S.P

= 7200 – 5400

= ₹ 1800

Further

Loss% = ( (Loss/C.P) x 100 ) %

Loss% = ( (1800/7200) x 100 ) %

= 25 %





20.Ashok bought a laptop costing ₹ 40000 and paid ₹ 1000 transportation charges . Then Ashok Sold it for ₹ 40590 . Find his loss percent ?

(a) 6 %

(b) 1 %

(c) 4 %

Answer

Answer: (b) 1 %

Explanation: C.P of laptop = ₹ 40000

Transportation charges = ₹ 1000

Transportation charge is an overhead expenses

Overhead expenses = Overhead expenses are certain other expenses incurred by the Seller, and hence are added to his cost price.

Therefore,

Total Cost Price = Cost price + Transportation charges

Total Cost Price = 40000 + 1000

= ₹ 41000

S.P of laptop = ₹ 40590

Clearly,

C.P > S.P

This indicates that some loss has been incurred

Therefore,

Loss = Total Cost Price – S.P

= 41000 – 40590

= ₹ 410

Since,

Loss% = ( (Loss/C.P) x 100 ) %

= ( (410/41000) x 100 ) %

= 1 %

Hence, Loss% = 1 %


 

21.A refrigerator is purchased for ₹ 27000 . If 10 % discount is allowed on its marked price and it still results in a gain of 5 % , find the marked price of the refrigerator ?

(a) ₹ 31800

(b) ₹ 31500

(c) ₹ 31600

Answer

Answer: (b) ₹ 31500

Explanation: Cost price of refrigerator = ₹ 27000

Discount% = 10 %

M.P = ?

Gain % = 5 %

M.P(marked price) = The price tagged on an article is called it’s marked price.

Discount = The offer of percentage of concession or rebate on the marked price is called Discount.

S.P = ((100+gainpercent)/100)×C.P

S.P = ((100+5)/100) x 27000

= (105/100) x 27000

S.P = ₹ 28350

Since Discount is always given on Marked price

Discount = 10 % of Marked price

Let the M.P be = ₹ x

Discount = (10/100) x x

Or

= 1x/10

S.P = M.P – Discount

= x – (1x/10)

= 10x−(1x/10)

S.P = 9x/10

But, the S.P calculated above = ₹ 28350

So,

9x/10 = 28350

x = (28350×10)/9

x = ₹ 31500

Hence, the Marked price = ₹ 31500


 

22.Ashok bought a bag of cement for ₹ 9176 including 24 % GST . Find the original price of the bag of cement ?

(a) ₹ 7325

(b) ₹ 7100

(c) ₹ 7400

Answer

Answer: (c) ₹ 7400

Explanation: Let the original price of bag of cement be = x

GST = 24 %

GST (Goods and Services Tax) = GST is an indirect tax levied on goods and services.

GST = 24 % x original price of bag of cement

= (24/100) x x

= ₹ (6/25) x x

Price including GST = x + (6/25) x x

= (25x+6x)/25

= ₹ 31x/25

But the price included GST is given = ₹ 9176

Therefore,

31x/25 = 9176

x = (9176 × 25)/31

x = 7400

Hence, the original price of bag of cement = ₹ 7400


 

23.If the price of a watch is ₹ 8200 , and 5 % sales tax charged on such cost , find the total money charged from the customer for sale of watch ?

(a) ₹ 7610

(b) ₹ 8710

(c) ₹ 8610

Answer

Answer: (c) ₹ 8610

Explanation: Price of watch = ₹ 8200

Sales tax = 5 %

Sales tax = Sales tax is charged by shopkeeper from the customer on selling price of an item.

Sales tax = 5 % of Price of watch

= (5/100) x 8200

= ₹ 410

Therefore,

The total price charged from the customer for watch = Price of watch + Sales tax

= ₹ ( 8200 + 410 )

= ₹ 8610


 

24. If the price of a transistor is ₹ 12000 , and 8 % sales tax charged on such cost , find the total money charged from the customer for sale of transistor ?

(a) ₹ 12760

(b) ₹ 12960

(c) ₹ 11960

Answer

Answer: (b) ₹ 12960

Explanation: Price of transistor = ₹ 12000

Sales tax = 8 %

Sales tax = Sales tax is charged by shopkeeper from the customer on selling price of an item.

Sales tax = 8 % of Price of transistor

= (8/100) x 12000

= ₹ 960

Therefore,

The total price charged from the customer for transistor = Price of transistor + Sales tax

= ₹ ( 12000 + 960 )

= ₹ 12960


 

Comparing Quantities Class 8 MCQ Questions with Answers

25.Find the Cost price when the S.P ₹ 2700 and Loss% is 10 % ?

(a) ₹ 2500

(b) ₹ 3000

(c) ₹ 2880

Answer

Answer: (b) ₹ 3000

Explanation: Given

S.P = ₹ 2700

Loss% = 10 %

C.P = ?

Cost Price (CP) – Price at which an Article is purchased.

Selling Price (SP) – Price at which the Article is sold.

Gain – Where the Selling Price is greater than the Cost Price, the difference between the SP and CP is the gain

Using formula to find C.P when Loss% and S.P are given

C.P = (100/(100−loss percent))×S.P

Substituting the value of Loss% and C.P in formula

C.P = (100/((100−10)) x 2700

= (100/90) x 2700

C.P = ₹ 3000


 

26.If the marked price of an article is ₹ 74000 and 15 % discount is allowed on its sales , find the selling price of the article ?

(a) ₹ 62950

(b) ₹ 62900

(c) ₹ 62800

Answer

Answer: (b) ₹ 62900

Explanation: Marked price of an article = ₹ 74000

Discount = 15 %

M.P (Marked price) = The price tagged on an article is called it’s marked price.

Discount = The offer of percentage of concession or rebate on the marked price is called Discount.

Since Discount is always given on Marked price

Therefore,

Discount = 15 % of Marked price

= 15 % x 74000

= (15/100) x 74000

= ₹ 11100

So,

S.P = Marked price – Discount

= 74000 – 11100

S.P = ₹ 62900





27.If we sell a radio for ₹ 1400 , 30 % is lost . At what price must it be sold to gain 20 % ?

(a) ₹ 2400

(b) ₹ 2406

(c) ₹ 2410

Answer

Answer: (a) ₹ 2400

Explanation: In order to solve this problem, we would need to first find the Cost price of the Shirt given the SP and loss %.

Once we know the cost, we can find the revised Selling Price, given the new profit percentage on Cost

Finding the Cost Price

S.P of radio = ₹ 1400

Loss % = 30 %

Here C.P can be calculated

C.P = (100/(100−loss percent)) x S.P

C.P = (100/(100−30)) x 1400

= (100/70) x 1400

C.P = ₹ 2000

Now we know that the shirt has been sold at Gain = 20 %

Gain % = 20 %

S.P = ?

Since,

C.P = ₹ 2000

S.P = ((100+gain percent))/100)x C.P

= ((100+20)/100) x 2000

= (120/100) x 2000

S.P = ₹ 2400

So, the radio must be sold at ₹ 2400


 

28.An amount of Rs. 3000 is compounded annually at the rate of 10 % p.a. The amount to be paid after 3 years would be ?

(a) Rs. 3993

(b) Rs. 3793

(c) Rs. 4243

Answer

Answer: (a) Rs. 3993

Explanation: From the given question, we can say

Principal = Rs. 3000

Rate = 10 %

Time (denoted by ‘n’) = 3 years

Computation of Maturity Amount

We know that

Amount = Principal x (1+(Rate/100))n

Amount = 3000 x (1+(10/100))3

Amount = 3000 x ((100+10)/100)3

Amount = 3000 x(110/100)3

Amount = 3000 x(11/10)3 (Dividing both 110 and 100 by 10 )

Amount = 3000 x (11/10) x (11/10) x (11/10)

Amount = 3993000/1000

Amount = 3993

Hence if An amount of Rs. 3000 is compounded annually at the rate of 10 % p.a. for 3 years , amount to be paid after 3 years would be = 3993.​


 

29.Find amount , if a sum of ₹ 80000 is compounded annually for 2 years The rates of interest for 2 years are : First Year = 5 % p.a. Second Year = 10 % p.a.

(a) 92600

(b) 92500

(c) 92400

Answer

Answer: (c) 92400

Explanation: In order to solve this problem, we would need to calculate Compound Interest for given years individually.

The amount for computing interest for second year will change to (Amount of Year 1 + Interest for Year 1)

Computation of Amount at the end of Year 1

Amount = Principal x (1+(Rate/100))n

Amount = 80000 x (1+(5/100))1

Amount = 80000 x (105/100)1

Amount = 80000 x (21/20)

Amount = 84000

Amount at the End of Year 1 = Principal at the beginning of Year 2

Computation of Amount at the end of Year 2

Amount = Principal x (1+(Rate/100))n

= 84000 x (1+(10/100))1

= 84000 x (110/100)1

= 84000 x (11/10)

= 92400

Hence, the Amount = ₹ 92400


 

30.The Compound interest on ₹ 9500 at 10 % p.a. for 2 years would be ?

(a) ₹ 1989

(b) ₹ 1985

(c) ₹ 1995

Answer

Answer: (c) ₹ 1995

Explanation: From the given question, we can say

Principal = ₹ 9500

Rate = 10 %

Time (denoted by ‘n’) = 2 years

We know that

Amount = Principal + Compound Interest

or

Compound Interest = Amount – Principal

In order to solve this problem, we would need to find out Amount, since Principal is already given

Computation of Maturity Amount

Amount = Principal (1+(Rate/100))n

Amount = 9500 (1+(10/100))2

Amount = 9500 x (110/100)2

Amount = 9500 x (11/10)2

Amount = 9500 x (11/10) x (11/10)

Amount = 1149500/100

Amount = 11495

Compound Interest = Amount – Principal

Compound Interest = 11495 – 9500

= 1995

Therefore, the Compound Interest = ₹ 1995


 

Comparing Quantities Class 8 MCQ Questions with Answers

31.The Compound interest on ₹ 1280000 at 30 % p.a. for 2 years is ?

(a) ₹ 958678

(b) ₹ 958828

(c) ₹ 958728

Answer

Answer: (c) ₹ 958728

Explanation: From the given question, we can say

Principal = Rs. 1280000

Rate = 15 % p.a.

(Since we have to compound the interest half-yearly i.e. two times in a year after every 6 months, we will divide the given rate by 2 as the Rate in the Formula for Amount is given Annually)

No. of Times Compounding is done (denoted by ‘n’) = 4 times

(Since the compounding is done half yearly, we will multiply the YEARS i.e. Time by 2)

We will first compute Amount and thereafter take the difference of Principal and Amount to find the Compound Interest.

Computation of Maturity amount

,

Amount = Principal x (1+(Rate/100))n

Amount = 1280000 x (1+(15/100))4

Amount = 1280000 x (115/100)4

Amount = 1280000 x (23/20) x (23/20) x (23/20) x (23/20)

Amount = 1280000 x (279841/160000)

Amount = 8 x 279841

Amount = 2238728

Compound Interest = 2238728 – 1280000

= 958728


 

32.The Compound interest on ₹ 8000 at 5 % p.a. for 3 years would be ?

(a) ₹ 1141

(b) ₹ 1511

(c) ₹ 1261

Answer

Answer: (c) ₹ 1261

Explanation: From the given question, we can say

Principal = Rs. 8000

Rate = 5 %

Time (denoted by ‘n’) = 3 years

In order to solve this problem, we would need to find out Amount, since Principal is already given

Computation of Maturity Amount

Amount = Principal x (1+(Rate/100))n

Amount = 8000 x (1+(5/100))3

= 8000 x (105/100)3

= 8000 x (21/20)3

= 8000 x (21/20) x (21/20) x (21/20)

= 74088000/8000

= 9261

Compound Interest = 9261 – 8000

= 1261

Hence, the Compound Interest = ₹ 1261





33.The difference between Simple Interest and Compound Interest on ₹ 30000 for 1 year at the rate of 40 % p.a. computed quarterly is ?

(a) ₹ 1925

(b) ₹ 1923

(c) ₹ 1926

Answer

Answer: (b) ₹ 1923

Explanation: We would compute both Simple Interest and Compound Interest individually for the given data, and then take their difference.

We are given that the

Principal = ₹ 30000

Rate = 10 % p.a.

(Since we have to compound the interest quarterly i.e. four times in a year after every 3 months, hence we will divide the given rate by 4)

No. of Times Compounding is done (denoted by ‘n’) = 4 times

Computation of Compound Interest

Amount = Principal x (1+(Rate/100))n

where ‘n’ denotes the number of times compounding is done. Like in this question compounding is done 4 times.

Amount = 30000 x (1+(10/100))4

Amount = 30000 x (110/100)4

Amount = 30000 x (110/100) x (110/100) x (110/100) x (110/100)

Amount = 30000 x (11/10) x (11/10) x (11/10) x (11/10)

Amount = 30000 x (14641/10000)

Amount = 3 x 14641

Amount = 43923

Compound Interest = 43923 – 30000

= 13923

Computation of Simple Interest

Simple Interest = (Principal × Rate × Time)/100

Simple Interest = (30000×40×4)/100

Simple Interest = 1200000/100

Simple Interest = 12000

Difference between Simple and Compound interest = Compound Interest – Simple Interest

= 13923 – 12000

Hence, the difference between Compound Interest and Simple Interest = ₹ 1923


 

34.The difference between Simple Interest and Compound Interest on Rs. 3000 for 1 year at the rate of 20 % p.a. computed half-yearly is ?

(a) 33

(b) 32

(c) 30

Answer

Answer: (c) 30

Explanation: We would compute both Simple Interest and Compound Interest individually for the given data, and then take their difference.

We are given that the

Principal = Rs. 3000

Rate = 10 % p.a.

(Since we have to compound the interest half-yearly i.e. two times in a year after every 6 months, we will divide the given rate by 2 as the Rate in the Formula for Amount is given Annually)

No. of Times Compounding is done (denoted by ‘n’) = 2 times

(Since the compounding is done half yearly, we will multiply the YEARS i.e. Time by 2)

Computation of Compound Interest

Amount = Principal x (1+(Rate/100))n

where ‘n’ denotes the number of times the Compounding is required to be done.

Amount = 3000 x (1+(10/100))2

Amount = 3000 x (110/100)2

Amount = 3000 x (110/100) x (110/100)

Amount = 36300000/10000

Amount = 3630

Compound Interest = 3630 – 3000

= 630

Computation of Simple Interest

Simple Interest = (Principal × Rate × Time)/100

Simple Interest = (3000×20×1)/100

Simple Interest = 60000/100

Simple Interest = 600

Difference between Simple and Compound interest = Compound Interest – Simple Interest

630 – 600

Hence the difference between Compound Interest and Simple Interest = 30


 

35.The difference between Simple Interest and Compound Interest on Rs. 5500 for 1 year at the rate of 15 % p.a. compounded annually would be ?

(a) 0

(b) 50

(c) 20

Answer

Answer: (a) 0

Explanation: We would compute both Simple Interest and Compound Interest individually for the given data, and then take their difference.

We are given that the

Principal = Rs. 5500

Rate = 15 % p.a.

Time (denoted by ‘n’) = 1 year

Computation of Compound Interest

Amount = Principal x (1+(Rate/100))n

Amount = 5500 x (1+(15/100))1

Amount = 5500 x (115/100)1

Amount = 5500 x (115/100)1

Amount = 5500 x (23/20)

Amount = 275 x 23

Amount = 6325

Compound Interest = 6325 – 5500

= 825

Amount

Simple Interest = (Principal × Rate × Time)/100

= (5500×15×1)/100

= 82500/100

= 825

The difference between Simple Interest and Compound Interest on = Compound Interest – Simple Interest

= 825 – 825

= 0


 

36.An amount of Rs. 2800 is compounded annually at the rate of 10 % p.a. The amount to be paid after 2 years would be ?

(a) Rs. 3388

(b) Rs. 3238

(c) Rs. 3614

Answer

Answer: (a) Rs. 3388

Explanation: From the given question, we can say

Principal = Rs. 2800

Rate = 10 %

Time (denoted by ‘n’) = 2 years

Computation of Maturity Amount

We know that

Amount = Principal x (1+(Rate/100))n

Amount = 2800 x (1+(10/100))2

= 2800 x(110/100)2 (Dividing both 110 and 100 by 10 )

= 2800 x(11/10)2

= 2800 x (11/10) x (11/10)

= 338800/100

= 3388

Hence, if An amount of Rs. 2800 is compounded annually at the rate of 10 % p.a. for 2 years , The amount to be paid after years would be = Rs. 3388


 

Comparing Quantities Class 8 MCQ Questions with Answers

37.A certain sum of money amounts to ₹ 44100 in 2 years at 5 % p.a. compounded annually . Find the sum ?

(a) ₹ 40100

(b) ₹ 40000

(c) ₹ 40200

Answer

Answer: (b) ₹ 40000

Explanation: We will compute the Sum by of Amount.

Amount = ₹ 44100

Rate = 5 %

Time (denoted by ‘n’) = 2 years

Let the Principal/Sum be Rs. P

Amount = Principal x (1+(Rate/100))n

44100 = P x (1+(Rate/100))2

44100 = P x (105/100)2

44100 = P x (21/20)2

44100 = P x (21/20) x (21/20)

44100 = P x (441/400)

44100 x (400/441) = P

17640000/441 = P

40000 = P

Hence, the Sum = ₹ 40000





38.In what time will Rs. 15625 amount to Rs. 21952 at 12 % p.a. when compounded annually ?

(a) 4

(b) 3

(c) 5

Answer

Answer: (b) 3

Explanation: We will compute TIME by of Amount.

Let us assume TIME to be ‘n’

Amount = Principal x (1+(Rate/100))n

21952 = 15625 x(1+(12/100))n

2195215625 = (1+(3/25))n

2195215625 = (28/25)n

We know that cube of 28 results in 21952 and cube of 25 results in 15625 .

(28/25)3 = (28/25)n

Since the Base is common, the index would remain the same

or

n = 3


 

39. The Population of a town was 20000 in the year 1997 It increases at the rate of 12 % p.a. What would be it population at the end of the year 1999 ?

(a) 26088

(b) 25088

(c) 23588

Answer

Answer: (b) 25088

Explanation: Since the increase in population would be based on new population at the end of previous year, this problem can be solved using formula of Compounding of Interest

In this question, instead of AMOUNT we have = Population in the Year 1999

The PRINCIPAL is similar to the beginning population, i.e., Population in the Year 1997

Further the difference of Years will be equal to the time period ‘n’.

Difference of Years = 1999 – 1997 = 2

Population in the year 1997 = 20000

Rate of Increase = 12 % p.a.

Population in 1999 = Population 1997 x (1+(Rate/100))n

= 20000 x (1+(12/100))2

= 20000 x (112/100)2

= 20000 x (28/25)2

= 20000 x (28/25) x (28/25)

= 20000 x (784/625)

= 32 x 784

= 25088

Hence, the Population at the end of the year 1999 would be = 25088


 

40. The Population of a town is 133100 in the year 2004 It increased at the rate of 10 % p.a. Find the Population in 2002 ?

(a) 111000

(b) 110000

(c) 109500

Answer

Answer: (b) 110000

Explanation: Since the increase in population would be based on new population at the end of previous year, this problem can be solved using formula of Compounding of Interest

In this question, instead of AMOUNT we have = Population in the year 2004

The PRINCIPAL is similar to the beginning population, i.e., = Population in the year 2002

Further the difference of Years will be equal to the time period ‘n’.

Difference of Years = 2004 – 2002

= 2

Population in the year = 133100

Rate of Increase = 10 % p.a.

Population in the year 2004 = Population in the year 2002 x (1+(Rate/100))n

133100 = Population in the year 2002 x (1+(10/100))2

133100 = Population in the year 2002 x (110/100)2

133100 = Population in the year 2002 x (11/10)2

133100 = Population in the year 2002 x (11/10) x (11/10)

133100 = Population in the year 2002 x (121/100)

Population in the year 2002 = 133100 x (100/121)

Population in the year 2002 = 1100 x 100

Population in the year 2002 = 110000

Hence, the Population in the year 2002 was = 110000


 

41.An amount of ₹ 650000 is compounded half yearly at the rate of 20 % p.a. The amount to be paid after 2 years would be ?

(a) ₹ 951765

(b) ₹ 951665

(c) ₹ 951615

Answer

Answer: (b) ₹ 951665

Explanation: From the given question, we can say

Principal = Rs. 650000

Rate = 10 % P.a.

(Since we have to compound the interest half-yearly i.e. two times in a year after every 6 months, we will divide the given rate by 2 as the Rate in the Formula for Amount is given Annually)

No. of Times Compounding is done (denoted by ‘n’) = 4 times

(Since the compounding is done half yearly, we will multiply the YEARS i.e. Time by 2)

Computation of Maturity Amount

Amount = Principal x (1+(Rate/100))n

Amount = 650000 x (1+(10/100))4

Amount = 650000 x (110/100)4

Amount = 650000 x (11/10)4

Amount = 650000 x (14641/10000)

Amount = 65 x 14641

= 951665

Hence, the Amount to be paid at end of 2 years would be = ₹ 951665


 

42.At what rate per cent p.a. will a sum Rs. 6250 amount to Rs. 7840 in 2 years when compounded annually ?

(a) 12 % p.a.

(b) 14 % p.a.

(c) 10 % p.a.

Answer

Answer: (a) 12 % p.a.

Explanation: We will compute RATE by of Amount.

Amount = Principal x (1+(Rate/100))n

7840 = 6250 x (1+(Rate/100))2

7840/6250 = (1+(Rate/100))2

784/625 = (1+(Rate/100))2

28/25 = 1 +(Rate/100)

(28/25) – 1 =Rate/100

3/25 = Rate/100

Rate = (3×100)/25

12 = Rate

Hence, the Rate per cent p.a is 12 %


 

MCQ Questions for Class 8 Maths with Answers

Frequently Asked Questions on Comparing Quantities Class 8 MCQ Questions

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