Sally made the conjecture that the sum of any two prime numbers is a prime number.

Which equation is a counterexample to her conjecture?

A.
15 + 4 = 19

B.
2 + 5 = 7

C.
3 + 11 = 14

D.
2 + 11 = 13

@blurbendy

Question

Sally made the conjecture that the sum of any two prime numbers is a prime number.
 
Which equation is a counterexample to her conjecture?
 
 A.
15 + 4 = 19
 
 B.
2 + 5 = 7
 
 C.
3 + 11 = 14
 
 D.
2 + 11 = 13


@blurbendy

anonymous · Answer

is it B

blurbendy · Answer

no, you want a counter example, so you want something that adds two primes together, but ends with a COMPOSITE solution.

anonymous · Answer

so c  ? cuz its 2 prime

blurbendy · Answer

C doesnt have a 2 in it, but it is the correct answer because 3 is prime, and a 11 is prime, but 14 is composite.

anonymous · Answer

ya its has 2 prime number and thx

blurbendy · Answer

oh, I see what you're saying.