question:A train 210 m long, running with a speed of 63 km/hr will pass a tree in?
Options:
(A) 18 sec
(B) 16 sec
(C) 76 sec
(D) 12 sec
(E) 17 sec
answer:(D)
Stream of consciousness:Speed = 63 * 5/18 = 35/2 m/sec
Time taken = 210 * 2/35 = 12 sec


question:Three people took GMAT practice tests in which the minimum and maximum possible scores are 200 and 800, respectively. They each took a test 5 times, and no one scored below 600 or over 760. If the individual ranges of the three people's scores in those 5 practice tests were 20, 60 and 90, what is the difference between the maximum and minimum possible ranges of all their scores put together.
Options:
(A) 40
(B) 60
(C) 70
(D) 100
(E) 110
answer:(C)
Stream of consciousness:According to the information in the question the maximum range would be between 600 and 760(160). The minimum range would be the greatest range for any one individual, which is listed in the problem as 90. So the difference between these would be 160-90 or 70.


question:In a race of 150 m, A gives B a start of 20 m. What distance will be covered by B ?
Options:
(A) 100 m
(B) 130 m
(C) 170 m
(D) 160 m
(E) 180 m
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
(B)
Stream of consciousness:Required distance = (150 - 20) m = 130 m