q: In how many ways can you seat 6 people on a bench if one of them, Rohit, does not want to sit on the middle seat or at either end?
Options:
(A) 360
(B) 1720
(C) 2880
(D) 5040
(E) 10080
a: Stream of consciousness: Since Rohit does not want to sit on the middle seat or at either end (3 chairs), then he can choose 3 chairs to sit. The remaining 5 people can sit in 5! ways. Thus the # of arrangements is 3*5! = 360. The answer is (A).

question: A and B can do a work in 10 days and 15 days respectively. A starts the work and B joins him after 3 days. In how many days can they complete the remaining work?
Options:
(A) 6 days
(B) 2 days
(C) 8 days
(D) 4 1/5 days
(E) 9 days
answer: Stream of consciousness: Work done by A in 3 days = 3/10
Remaining work = 7/10
Work done by both A and B in one day = 1/10 + 1/15 = 5/30 = 1/6
Remaining work = 7/10 * 6/1 = 21/5 = 4 1/5 days. The answer is (D).

q: The flow of water through a drainage pipe was monitored for a 3-hour period. In the second hour, the rate of flow was 12 gallons per hour, which was 50 percent faster than the rate of flow for the first hour. If 25 percent more water flowed through the pipe in the third hour than it did in the second, how many gallons of water flowed through the pipe during the entire three hours?
Options:
(A) 31.25
(B) 31.5
(C) 33.75
(D) 35.0
(E) 37.5
a: Stream of consciousness: Rate of flow of water in second hour = 12 gallons per hour
Rate of flow of water in first hour = 12/(3/2) = 8 gallons per hour
Rate of flow of water in third hour = (125/100)* 12 = (5/4) * 12 = 15 gallons per hour
Number of gallons of water that flowed through the pipe during the entire 3 hours = 12+8+15 = 35 gallons The answer is (D).

question: If 100!/30^n is an integer, which of the following is the greatest possible value of n?
Options:
(A) 28
(B) 24
(C) 20
(D) 15
(E) 10
answer: Stream of consciousness: 30^n = 2^n * 3^n * 5^n
100! has 97 2's, 48 3's and 24 5's
Since each of 2, 3 and 5 is required to form 30 and there are only 24 5's there can only be 24 30's in 100! The answer is (B).

q: What percent is 240 of 90?
Options:
(A) 133 1/3 %
(B) 134 1/3 %
(C) 135 1/3 %
(D) 266 2/3 %
(E) 143 1/3 %
a: Stream of consciousness: 240/90 = 8/3
8/3 100 = 800/3 = 266 2/3 % The answer is (D).

q: How many seconds will a train 120 meters long take to cross a bridge 150 meters long if the speed of the train is 36 kmph?
Options:
(A) 27 sec
(B) 23 sec
(C) 24 sec
(D) 25 sec
(E) 26 sec
a:
Stream of consciousness: D = 120 + 150 = 270
S = 36 * 5/18 = 10 mps
T = 270/10 = 27 sec The answer is (A).