Question 5

(a)

(b)

Use either the method of contraposition or the method of contradiction to prove that if

n, m, p are positive integers such that

n² +50

3m+2p

then either m≤4, or p ≤6, or n≥11.

(6 marks)

≥6

(8 marks)

Let a, b be integers. Show that if 3a²+2b³ leaves a reminder of either 0 or 3 when

divided by 5, then 3a+2b does not leave a remainder of 1 when divided by 5.

(10 marks)