LET N BE AN INTEGER GREATER THAN 6. PROVE THAT IF N − 1 AND N + 1 A...

1. Let n be an integer greater than 6. Prove that if n − 1 and n + 1 are

both prime, then n

2

( n

2

+ 16) is divisible by 720. Is the converse true?

Time allowed 3

12

hours.

Instructions • Full written solutions - not just answers - are

required, with complete proofs of any assertions