how many positive intergres less than 20 are equal to the sum of two different prime number?

2 answers

well, the primes less than 20 are
2,3,5,7,11,13,17,19

So, pick all the pairs that add up to less than 20.
2+3=5,2+5=7,2+7=9,2+11=13,2+13=15,2+17=19,

3+5=8, 3+7=10, 3+11=14, 3+13=16,

5+7=12, 5+11=16, 5+13=18,

7+11=18

So, is 14

am i right?
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