Question

The sum of two prime numbers is 85. What is the product of these two prime numbers?

Answer 1

I am thinking : what two things can be add up to make 5? there are many possibilities, but one will have to be even and one odd. (the only way to add up to an odd number).And the only even prime number is 2! so the two numbers have to be 2 and 83!

and their product is 2*83=166!