Question

How many multiples of 10 can be written as the sum of three different primes less than 20?

Answer 1

Answer:

Prime numbers less than 20 are 2, 3, 5, 7, 11, 13, 17 and 19.

(i) 2+3=5 (divisible by 5)

(ii) 2+13= 15 (divisible by 5)

(iii) 3+7=10 (divisible by 5)

(iv) 3+17= 20 (divisible by 5)

(v) 7+13=20 (divisible by 5)