q: A train 640 m in length crosses a telegraph post in 16 seconds. The speed of the train is?
Options:
(A) 22 kmph
(B) 77 kmph
(C) 144 kmph
(D) 71 kmph
(E) 88 kmph
a: OK... S = 640/16 * 18/5 = 144 kmph
The answer is (C).

q: There are 3 teams each with 4 basket players. How many combinations are there if we were to pick 2 players from the 3 teams such that no team was picked twice?
Options:
(A) 50
(B) 23
(C) 48
(D) 28
(E) 45
a: OK... There are altogether three arrangements, which are we can select two members each from team A and B, each from team A and C, and each from team B and C. For each arrangement, there are altogether 16 possibilities (4*4) since each team has 4 players. So there are a total of 48 possibilities (16*3). I hope this method is easier for you to understand.
The answer is (C).

q: A man walks at a speed of 3 km/hr and runs at a speed of 7 km/hr. How much time will the man require to cover a distance of 10 1/2 km, if he completes half of the distance, i.e., (5 1/4) km on foot and the other half by running?
Options:
(A) 2 1/2
(B) 2 1/6
(C) 4 1/2
(D) 2 1/1
(E) 2 1/8
a:
OK... Required time = (5 1/4)/3 + (5 1/4)/7 = 2 1/2 hours.
The answer is (A).