q: Pipe A can fill a tank in 5 hours, pipe B in 10 hours and pipe C in 30 hours. If all the pipes are open, in how many hours will the tank be filled?
Options:
(A) 2
(B) 3
(C) 3.5
(D) 4
(E) 4.5
a: Stream of consciousness: Part filled by A + B + C in 1 hour = 1/5 + 1/10 + 1/30 = 1/3
All the three pipes together will fill the tank in 3 hours. The answer is (B).

question: If a and b are unique prime integers, which of the following must be odd?
Options:
(A) ab
(B) 2a+2b
(C) 2a2b
(D) 2a / 2b
(E) ab^2
answer: Stream of consciousness: Any number multiplied by 2 has to be an even number. hence The answer is (A).

q: A and B together can complete a work in 12 days. A alone can complete it in 20 days. If B does the work only for half a day daily, then in how many days A and B together will complete the work?
Options:
(A) 11 days
(B) 77 days
(C) 15 days
(D) 18 days
(E) 19 days
a: Stream of consciousness: B's 1 day work = (1/12 - 1/20) = 1/30
Now, (A + B)'s 1 day work = (1/20 + 1/60) = 1/15
So, A and B together will complete the work in 15 days. The answer is (C).

question: 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 1.2 km long?
Options:
(A) 2 mins 14 sec
(B) 2 mins 34 sec
(C) 162 sec
(D) 244 sec
(E) 2 mins 44 sec
answer: Stream of consciousness: D = 25 * 60 + 1200 = 2700 m
T = 2700/60 * 18/5 = 162 se The answer is (C).

q: Some persons can do a piece of work in 12 days. Two times the number of these people will do half of that work in?
Options:
(A) 3 days
(B) 6 days
(C) 8 days
(D) 4 days
(E) 9 days
a: Stream of consciousness: 12/ (2 * 2) = 3 days The answer is (A).

q: A no.when divided by 224 gives a remainder 43, what remainder will beobtained by dividingthe same no.17?
Options:
(A) 2
(B) 7
(C) 9
(D) 11
(E) 12
a:
Stream of consciousness: 224 + 43 = 267/17 = 12 (Remainder) The answer is (E).