q: Which of the following is equal to (x-1)!/(x-2)!?
Options:
(A) x-1
(B) 1+(1/x)
(C) 1
(D) x+1
(E) x-1
a: Stream of consciousness: (x - 1)! = (x - 2)! * (x-1)
(x - 1)!/(x-2)! = x - 1 The answer is (E).

question: 100 white and black tiles will be used to form a 20x20 square pattern. If there must be at least one black tile in every row and at least one white tile in every column, what is the maximum difference between the number of black and white tiles that can be used?
Options:
(A) 75
(B) 70
(C) 85
(D) 90
(E) 95
answer: Stream of consciousness: Answer = B
Please refer diagram below
90 - 20 = 70 The answer is (B).

q: If rupee one produces rupees nine over a period of 40 years, find the rate of simple interest?
Options:
(A) 22 1/9 %
(B) 22 2/2 %
(C) 23 1/2 %
(D) 22 1/2 %
(E) 62 1/2 %
a: Stream of consciousness: 9 = (1*40*R)/100
R = 22 1/2 % The answer is (D).

question: If rupee one produces rupees nine over a period of 40 years, find the rate of simple interest?
Options:
(A) 22 1/7 %
(B) 22 3/2 %
(C) 22 1/8 %
(D) 22 1/2 %
(E) 22 1/2 %
answer: Stream of consciousness: 9 = (1*40*R)/100
R = 22 1/2 % The answer is (D).

q: A train of 24 carriages, each of 60 meters length, when an engine also of 60 meters length is running at a speed of 60 kmph. In what time will the train cross a bridge 1.4 km long?
Options:
(A) 2 mins 14 sec
(B) 2 mins 34 sec
(C) 2 mins 54 sec
(D) 4 mins 54 sec
(E) 2 mins 44 sec
a: Stream of consciousness: D = 25 * 60 + 1400 = 2900 m
T = 2900/60 * 18/5 = 174 sec = 2 mins 54 se The answer is (C).

q: A man rows his boat 65 km downstream and 45 km upstream, taking 2 1/2 hours each time. Find the speed of the stream?
Options:
(A) 5 kmph
(B) 4 kmph
(C) 9 kmph
(D) 8 kmph
(E) 1 kmph
a:
Stream of consciousness: Speed downstream = d/t = 65/(2 1/2) = 26 kmph
Speed upstream = d/t = 45/(2 1/2) = 18 kmph
The speed of the stream = (26 - 18)/2 = 4 kmph The answer is (B).