Which is the smallest no which divides 2880 and gives a perfect square?  Options:
A) 4
B) 9
C) 3
D) 5
E) 7

Rationale: 2880 = 20 * 144 ( because w . k . t 144 is perfect square ) = 2 * 10 * 144 = 2 * 2 * 5 * 144 = 4 * 5 * 144 ( here 4 and 144 are perfect square ) so the smallest number is 5 answer : d
Answer: D