question:A train running at the speed of 142 km/hr crosses a pole in 12 seconds. Find the length of the train.
Options:
(A) 540
(B) 288
(C) 200
(D) 340
(E) 712
answer:(A)
Stream of consciousness:Speed = 162*(5/18) m/sec = 45m/sec
Length of Train (Distance) = Speed * Time
45 * 12 = 540 meter

question:There are five same model cars parked in the same direction in parking. If 3 cars are red, 1 is black and 1 is green, in how many ways they can be arranged in the parking?
Options:
(A) 10 ways.
(B) 20 ways.
(C) 30 ways.
(D) 40 ways.
(E) 50 ways.
answer:(B)
Stream of consciousness:5!/(3!*1!*1!) = (5*4*3*2*1)/(3*2*1) = 120/6 = 20 ways.

question:A train 410 m long is running at a speed of 45 km/hr. In what time will it pass a bridge 140 m long?
Options:
(A) 40
(B) 87
(C) 26
(D) 21
(E) 44
answer:
(E)
Stream of consciousness:Speed = 45 * 5/18 = 25/2 m/sec
Total distance covered = 410 + 140 = 550 m
Required time = 550 * 2/25 = 44 sec