q: Two persons A and B can complete a piece of work in 30 days and 45 days respectively. If they work together, what part of the work will be completed in 3 days?
Options:
(A) 1/5
(B) 1/1
(C) 1/6
(D) 1/3
(E) 1/7
a: Stream of consciousness: A's one day's work = 1/30
B's one day's work = 1/45
(A + B)'s one day's work = 1/30 + 1/45 = 1/18
The part of the work completed in 3 days = 3 (1/18) = 1/6. The answer is (C).

question: A man, a woman and a boy can complete a job in 3, 4 and 12 days respectively. How many boys must assist 1 man and 1 woman to complete the job in 1/4 of a day?
Options:
(A) 22
(B) 77
(C) 26
(D) 41
(E) 66
answer: Stream of consciousness: (1 man + 1 woman)'s 1 day work = (1/3 + 1/4) = 7/12 Work done by 1 man and 1 woman in 1/4 day = (7/12 * 1/4) = 7/48
Remaining work = (1 - 7/48) = 41/48
Work done by 1 boy in 1/4 day = ( 1/12 * 1/4) = 1/48
Number of boys required = 41/48 * 41 = 41. The answer is (D).

q: A pipe can fill a cistern in 20 minutes whereas the cistern when full can be emptied by a leak in 28 minutes. When both pipes are opened, find when the cistern will be full?
Options:
(A) 17
(B) 16
(C) 70
(D) 13
(E) 12
a: Stream of consciousness: 1/20 - 1/28 = 1/70
70 minutes The answer is (C).

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: 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. The answer is (C).

q: A train 70 m long, running with a speed of 63 km/hr will pass a tree in?
Options:
(A) 4 sec
(B) 16 sec
(C) 6 sec
(D) 20 sec
(E) 8 sec
a: Stream of consciousness: Speed = 63 * 5/18 = 35/2 m/sec
Time taken = 70 * 2/35 = 16 sec The answer is (A).

q: Steve traveled the first 5 hours of his journey at 40 mph and the last 3 hours of his journey at 80 mph. What is his average speed of travel for the entire journey?
Options:
(A) 53.33 mph
(B) 88 mph
(C) 60 mph
(D) 64 mph
(E) 66.67 mph
a:
Stream of consciousness: Average Speed = Total distance/ Total time = (40 * 5 + 80 * 3)/(5 + 3) = 440/5 = 88 The answer is (B).