Express each of the following numbers as the sum of three odd primes: 

(a) 21         (b) 31          (c) 53          (d) 61

(a) 21 is obtained by adding the odd prime numbers 3, 5, and 13. i.e 21 = 3 + 5 + 13.

(b) 31 is obtained by adding the odd prime numbers 3, 5, and 23. i.e 31 = 3 + 5 + 23.

(c) 53 is obtained by adding the odd prime numbers 13, 17, and 23. i.e 53 = 13 + 17 + 23.

(d) 61 is obtained by adding the odd prime numbers 7, 13, and 41. i.e 61 = 7 + 13 + 41.