GMAT一道数学题 What is型提问要唯一解么?

GMAT一道数学题 What is型提问要唯一解么?
What is the remainder when the positive integer n is divided by the positive integer k,where k >
(1) n = (k+1)3
(2) k = 5
Statement (1) ALONE is sufficient,but statement (2) alone is not sufficient.
Statement (2) ALONE is sufficient,but statement (1) alone is not sufficient.
BOTH statements TOGETHER are sufficient,but NEITHER statement ALONE is sufficient.
EACH statement ALONE is sufficient.
为什么