Copyright © University of Cambridge. All rights reserved.

'Prime AP' printed from

Show menu

Why do this problem?
A non standard problem on prime numbers and AP's that requires some careful mathematical reasoning

Possible approach
Let the class work at first individually and then is small groups. Discuss their findings. If they have not met modulus arithmetic, or the usual notation, then introduce this notation as a standardised way of recording the reasoning in this solution.

Key questions
How can we be sure we have considered all possible cases?