Data Sufficiency

If k and n are integers, is n divisible
by 7?
(1) n - 3 = 2k
(2) 2k - 4 is divisible by 7.

OA is C

If k and n are integers, is n divisible by 7?

(1) n - 3 = 2k

n = 2k + 3
If k = 1, n = 5. n is not divisible by 7.
If k = 2, n = 7. n is divisible by 7.
Since we don't have a definite answer, statement I is insufficient to answer the question.

(2) 2k - 4 is divisible by 7.

2k - 4 = 7x, where x is an Integer.
2k = 7x + 4
Since we don't know the value of n, statement II is insufficient to answer the question.

From I and II

2k = 7x + 4 and n = 2k + 3
n = 7x + 4 + 3
n = 7x + 7
n = 7(x + 1)
n is a multiple of 7. So n is divisible by 7.

Answer : C