1989 AJHSME Problems/Problem 16
Problem
In how many ways can be written as the sum of two primes?
Solution
For to be written as the sum of two integers, one must be odd and the other must be even. There is only one even prime, namely , so one of the numbers must be , making the other .
However, is not prime, so there are no ways to write as the sum of two primes .
See Also
1989 AJHSME (Problems • Answer Key • Resources) | ||
Preceded by Problem 15 |
Followed by Problem 17 | |
1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22 • 23 • 24 • 25 | ||
All AJHSME/AMC 8 Problems and Solutions |