question: A train 280 m long, running with a speed of 63 km/hr will pass a tree in?
Options:
(A) 15 sec
(B) 16 sec
(C) 18 sec
(D) 20 sec
(E) 22 sec
answer: Stream of consciousness: Speed = 63 * 5/18 = 35/2 m/sec
Time taken = 280 * 2/35 = 16 sec The answer is (B).


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).


question: 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
answer: Stream of consciousness: 6 people can be prized with 4 distinct prizes in 6^4 ways The answer is (C).


q: The edge of a cube is 6a cm. Find its surface?
Options:
(A) 216a2
(B) 24a4
(C) 24a1
(D) 24a2
(E) 24a7
a: Stream of consciousness: 6a2 = 6 * 6a * 6a = 216a2 The answer is (A).


question: Two pipes can fill a tank in 20 and 24 minutes respectively and a waste pipe can empty 3 gallons per minute. All the three pipes working together can fill the tank in 15 minutes. The capacity of the tank is?
Options:
(A) 820 gallons
(B) 128 gallons
(C) 120 gallons
(D) 129 gallons
(E) 220 gallons
answer: Stream of consciousness: Work done by the waste pipe in 1 minute = 1/15 - (1/20 + 1/24) = - 1/40
Volume of 1/40 part = 3 gallons\
Volume of whole = 3 * 40 = 120 gallons. The answer is (C).


question: There are 4 magazines lying on a table; 2 are fashion magazines and the other 2 are sports magzines. If 1 magazines are to be selected at random from the 8 magazines, what is the probability that at least one of the fashion magazine will be selected?
Options:
(A) 1
(B) 1/2
(C) 1/4
(D) 1/6
(E) 1/8
answer:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Stream of consciousness: 1- (2c1/4c1) = 1-1/2 = 1/2 The answer is (B).