A prime number is a positive integer having exactly two factors. If p is a prime, then it’s only factors are necessarily 1 and p itself.
Except 2, all other prime numbers are odd. In other words, we can say that 2 is the only even prime number.
Solution
We need to express the given numbers as the sum of odd primes. The prime numbers between 1 and 50 are listed below:
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47.
So using the above any three odd primes we need to express as the sum of the given number.
(a) 21=3+7+11
(b) 31=3+11+17
(c) 53=13+17+23
(d) 61=19+29+13
