Express each of the following numbers as the sum of three odd primes (a) 21 (b) 31 (c) 53 (d) 61

Question – Express each of the following numbers as the sum of three odd primes (a) 21 (b) 31 (c) 53 (d) 61

Solution – 

First, We will write all the prime numbers between 1 and 70.

i.e., 2,3,5,7,11,13,17,19,23,29,31,37,41, 43, 47, 53, 59, 61, 67.

Here, 2 is an even prime number.

(a) 21 = 3 + 5 + 13

= 3 + 7 + 11

(b) 31 = 3 + 11 + 17

= 3 + 5 + 23

= 5 + 7 + 19

= 7 + 11 + 13

(c) 53 = 13 + 17 + 23

(d) 61 = 7 + 13 + 41

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