Question

If k is a positive integer and n = k(k + 7), is n divisible by 6 ? (1) k is odd. (2) When k is divided by 3, the remainder is 2.

Answer 1

1.) Yes

2.) Yes

Explanation:

Given that

n = k(k + 7)

If k is a positive integer and n = k(k + 7), is n divisible by 6 ?

(1) k is odd. Yes.

Let assume that k = 3

Then, n = 3(3 + 7)

n = 3 × 10

n = 30.

30 is divisible by 6.

(2) When k is divided by 3, the remainder is 2. That is,

Let k = 5

Then,

5/3 = 1 remainder 2

Substitute k into the equation

n = k(k + 7)

n = 5(5 + 7)

n = 5 × 12

n = 60

And 60 is divisible by 6.

Therefore, the answer to both questions is Yes.