Question: A man drives at a speed of 40 miles/hr. His wife left 30 mins. late with 50 miles/hr speed. when will they meet ?
Options:
(A) 1 hours
(B) 2 hours
(C) 3 hours
(D) 4 hours
(E) 5 hours
Answer: In 30 minutes the man would have droven 20 miles, when his wife starts. Now both are driving in the same direction. So speed of wife related to man is 10(50-40) miles/hr. So wife will cover 20 miles in 2 hours to meet the man.
The answer is (B).

Question: Which of the following is equal to the average (arithmetic mean) of (x+5)^2 and (x-5)^2?
Options:
(A) x^2
(B) x^2+2
(C) x^2 +30
(D) x^2+20
(E) x^2+25
Answer: Avg = [(x+5)^2 + (x-5)^2] / 2
Expanding and simplifying, (x^2 + 10x + 25 + x^2 - 10x + 25) / 2 = x^2 + 25
The answer is (E).

Question: X can finish a work in 24 days. Y can finish the same work in 16 days. Yworked for 10 days and left the job. how many days does X alone need to finish the remaining work?
Options:
(A) 3
(B) 5
(C) 6
(D) 8
(E) 9
Answer: Work done by X in 1 day = 1/24
Work done by Y in 1 day = 1/16
Work done by Y in 10 days = 10/16 = 5/8
Remaining work = 1 5/8 = 3/8
Number of days in which X can finish the remaining work = (3/8) / (1/24) = 9
The answer is (E).

Question: What is the maximum number of pieces of birthday cake of size 5" by 5" that can be cut from a cake 15" by 15"?
Options:
(A) 5
(B) 10
(C) 16
(D) 20
(E) 9
Answer:
The prompt is essentially asking for the maximum number of 5 x 5 squares that can be cut from a larger 15 by 15 square. Since each 'row' and each 'column' of the larger square can be sub-divided into 3 'pieces' each, we have (3)(3) = 9 total smaller squares (at maximum).
The answer is (E).