True or false: Whenever N, N - 10, N + 30, and N + 60 are all prime numbers, then so is N + 90.
Solution
False: When you come to N = 617, you'll get 607, 647, and 677, all primes, but 707 is not (= 101 x 7).
True or false: Whenever N, N - 10, N + 30, and N + 60 are all prime numbers, then so is N + 90.
False: When you come to N = 617, you'll get 607, 647, and 677, all primes, but 707 is not (= 101 x 7).