Question | Find the LCM and HCF of the following pairs of integers and verify that LCM × HCF = product of two numbers. |
Board | CBSE |
Textbook | NCERT |
Class | Class 10 |
Subject | Maths |
Chapter | Chapter 1 Real Numbers |
Question – Find the LCM and HCF of the following pairs of integers and verify that LCM × HCF = product of two numbers.
(i) 26 and 91
(ii) 510 and 92
(iii) 336 and 54
Solution:
We know that the HCF of two numbers is equal to the product of the smallest power of each common prime factor in the numbers.
And LCM of two numbers equal to the product of the greatest power of each prime factor, involved in the numbers.
(i) 26 and 91
26 = 2 × 13
91 = 7 × 13
Here 13 is common in both the prime factors of 26 and 91.
HCF of 26 and 91 is 13
LCM of these two numbers = 2 × 7 × 13 =182.
HCF × LCM = 13 × 182 = 2366
Product of 26 and 91 = 26 × 91 = 2366.
Hence, LCM × HCF = Product of the given two numbers
(ii) 510 and 92
510 = 2 × 3 × 5 × 17
92 = 2 × 2 × 23
Here, 2 is common in both the prime factors of 510 and 92
HCF of 510 and 92 is 2
LCM = 2 × 2 × 3 × 5 17 × 23 = 23460
HCF × LCM = 2 × 23460 = 46920
Product of 510 and 92 is = 510 × 92 = 46920.
Hence, LCM × HCF = Product of the given two numbers
(iii) 336 and 54
336 = 2 × 2 × 2 × 2 × 3 × 7
54 = 2 × 3 × 3 × 3
Here, 2 and 3 are common prime factors of 336 and 54.
HCF = 2×3 = 6
LCM = 2 × 2 × 2 × 2 × 3 × 3 × 3 × 7 = 3024
HCF × LCM = 6 × 3024 = 18144
Product of336 and 54 = 336 × 54 = 18144
Hence, LCM × HCF = product of the given two numbers
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