question: Two pipes A and B can fill a tank in 36 hours and 45 hours respectively. If both the pipes are opened simultaneously, how much time will be taken to fill the tank?
Options:
(A) 20 hrs
(B) 22 hrs
(C) 23 hrs
(D) 24 hrs
(E) 21 hrs
answer: Stream of consciousness: 1/( 1/36 +1/45) = 180/9 = 20 hrs The answer is (A).

q: How long does a train 110 m long traveling at 36 kmph takes to cross a bridge of 170 m in length?
Options:
(A) 28
(B) 16.0
(C) 16.4
(D) 16.8
(E) 16.1
a: Stream of consciousness: D = 110 + 170 = 280 m
S = 36 * 5/18 = 10
T = 280 * 1/10 = 28 sec The answer is (A).

question: Imagine a disk spinning like a record player turn table. Half of the disk is black and the other is white. Assume you have an unlimited number of color sensors. How many sensors would you have to place around the disk to determine the direction the disk is spinning? Where would they be placed?
Options:
(A) 1
(B) 2
(C) 3
(D) 4
(E) 5
answer: Stream of consciousness: 1 sensor between the black and white border on the edge of disk
1 is enough to determine the drection The answer is (A).

q: A 200 meter long train crosses a man standing on the platform in 9 sec. What is the speed of the train?
Options:
(A) 228
(B) 108
(C) 1266
(D) 188
(E) 80
a: Stream of consciousness: S = 200/9 * 18/5 = 80 kmph The answer is (E).

question: What will come in place of the x in the following Number series? 68, 36, 20, 12, 8, x
Options:
(A) 6
(B) 4
(C) 2
(D) 1
(E) 0
answer: Stream of consciousness: 68
68 / 2 + 2 = 36
36 / 2 + 2 = 20
20 / 2 + 2 = 12
12 / 2 + 2 = 8
8 / 2 + 2 = 6 The answer is (A).

question: There are two water tanks A and B, A is much smaller than B. While water fills at the rate of one liter every hour in A, it gets filled up like 10, 20, 40, 80, 160 in tank B. (At the end of first hour, B has 10 liters, second hour it has 20, third hour it has 40 and so on). If tank B is 1/32 filled after 21 hours, what is the total duration required to fill it completely?
Options:
(A) 22
(B) 28
(C) 269
(D) 26
(E) 82
answer:
Stream of consciousness: The data related to the first tank A is not necessary. As you can see, the capacity that gets filled in the tank B after each hour is doubled. So If the tank is 1/32nd part is full after 21 hours, it is 1/16th part full after 22 hours, 1/8th part full after 23 hours, 1/4th part full after 24 hours, 1/2 full after 25 hours, completely full after 26 hours. The answer is (D).