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 1.5 km long?
Options:
(A) 6
(B) 3
(C) 4
(D) 9
(E) 2
answer: Stream of consciousness: D = 25 * 60 + 1500 = 3000 m
T = 3000/60 * 18/5 = 180 sec = 3 mins The answer is (B).

q: Two pipes A and B can fill a cistern in 20 and 30 minutes respectively, and a third pipe C can empty it in 50 minutes. How long will it take to fill the cistern if all the three are opened at the same time?
Options:
(A) 17 1/4 min
(B) 28 1/7 min
(C) 17 1/7 min
(D) 17 1/8 min
(E) 15 15/19 min
a: Stream of consciousness: 1/20 + 1/30 - 1/50 = 19/300
300/19 = 15 15/19 The answer is (E).

question: A 600 meter long train crosses a signal post in 40 seconds. How long will it take to cross a 3 kilometer long bridge, at the same speed?
Options:
(A) 4 min
(B) 6 min
(C) 8 min
(D) 2 min
(E) 9 min
answer: Stream of consciousness: S = 600/40 = 15 mps
S = 3600/15 = 240 sec = 4 min The answer is (A).

q: In a race with 30 runners where 4 trophies will be given to the top 6 runners (the trophies are distinct: first place, second place, etc), how many ways can this be done?
Options:
(A) 8^8 ways
(B) 8^9 ways
(C) 6^4 ways
(D) 8^7 ways
(E) 8^6 ways
a: Stream of consciousness: 6 people can be prized with 4 distinct prizes in 6^4 ways The answer is (C).

question: A no.when divided by 158 gives a remainder 50, what remainder will be obtainedby dividingthe same no.16?
Options:
(A) 10
(B) 11
(C) 12
(D) 13
(E) 14
answer: Stream of consciousness: 158 + 50 = 208/16 = 13 (Remainder) The answer is (D).

question: 150 is increased by 40%. Find the final number.
Options:
(A) 200
(B) 210
(C) 180
(D) 190
(E) 220
answer:
Stream of consciousness: Final number = Initial number + 40%(original number) = 150 + 40%(150) = 150 + 60 = 210. The answer is (B).