Question

N is a positive integer
explain why n(n-1) must be an even number

Answer 1

if 'n' is positive and odd then reducing it by one gives you an even; so then you are multiplying and even and an odd which results in an even

if 'n' is positive and even then reducing it by one gives you an odd; so then you are multiplying and even and an odd which results in an even

Explanation: