question:For some integer n, n^2 - 5 is divisible by all of the following EXCEPT
Options:
(A) 41
(B) 38
(C) 29
(D) 30
(E) 31
answer:(D)
Stream of consciousness:Hint: n^2-5 (n is an integer) is never multiple of 3 (try to prove this), hence 30 is out.

question:Find the smallest number which should be multiplied with 1152 to make it a perfect square.
Options:
(A) 2
(B) 1
(C) 3
(D) 5
(E) 6
answer:(A)
Stream of consciousness:1152 = 2*2*2*2*2*2*2*3*3
Required smallest number = 2
2 is the smallest number which should be multiplied with 1152 to make it a perfect square.

question:The average of first 10 even numbers is?
Options:
(A) 17
(B) 199
(C) 16
(D) 11
(E) 123
answer:
(D)
Stream of consciousness:Sum of 10 even numbers = 10 * 11 = 110
Average = 110/10 = 11