Question: The average of five numbers is 41. The average of first two numbers is 32 and the average of last two numbers is 38. What is the middle number?
Options:
(A) 59
(B) 64
(C) 61
(D) 72
(E) 65
Answer: The total of five numbers = 5X41 = 205
The total of first 2 and last 2 numbers is = 2 X 32+2 X 38 = 140
So, the middle number is (205 - 140 ) = 65
The answer is (E).

Question: On average, the bottle-nosed dolphin comes up for air once every three minutes; the beluga whale, a close relative, comes up for air on average once every nine minutes. The number of times a bottle-nosed dolphin would come up for air in a 24 hour period is approximately what percent greater than the number of times a beluga whale would come up for air in that same period?
Options:
(A) 150%
(B) 200%
(C) 250%
(D) 300%
(E) 350%
Answer: Dolphin once in 3 min;
Beluga once in 9 min;
So, dolphin comes up 3 times frequently than beluga, which is 300% (9-3)/2*100.
The answer is (D).

Question: Find the third proportional to 4 and 16?
Options:
(A) 80
(B) 12
(C) 64
(D) 78
(E) 72
Answer: Formula = Third proportional = (b b)/a
A = 4 and B = 16
(16 16)/ 4 = 256/4 = 64
The answer is (C).

Question: What is the least value of integer N such that N! is divisible by 888 ?
Options:
(A) 13
(B) 88
(C) 31
(D) 37
(E) D) 888
Answer:
888 = 8*111 = 3*8*37
Hence 888 is a multiple of 37 and we need at least one 37 in N!
Therefore least value of N! is 37!, which will contain all of 3, 8, and 37.
The answer is (D).