question: 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 7 days?
Options:
(A) 2/5
(B) 7/18
(C) 1/4
(D) 1/9
(E) 2/6
answer: 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 7 days = 7 (1/18) = 7/18. The answer is (B).


q: A can do a piece of work in 15 days. When he had worked for 2 days B joins him. If the complete work was finished in 8 days. In how many days B alone can finish the work?
Options:
(A) 11 6/7days
(B) 12 6/7days
(C) 13 6/7days
(D) 14 6/7days
(E) 15 6/7days
a: Stream of consciousness: 8/15 + 6/x = 1
X = 12 6/7days The answer is (B).


question: By travelling at 40 kmph, a person reaches his destination on time. He covered two-third the total distance in one-third of the total time. What speed should he maintain for the remaining distance to reach his destination on time?
Options:
(A) 20
(B) 99
(C) 77
(D) 63
(E) 61
answer: Stream of consciousness: Let the time taken to reach the destination be 3x hours. Total distance = 40 * 3x = 120x km
He covered 2/3 * 120x = 80x km in 1/3 * 3x = x hours So, the remaining 40x km, he has to cover in 2x hours. Required speed = 40x/2x = 20 kmph. The answer is (A).


q: The area of a triangle is with base 12m and height 5m?
Options:
(A) 88 m2
(B) 30 m2
(C) 66 m2
(D) 77 m2
(E) 31 m2
a: Stream of consciousness: 1/2 * 12 * 5 = 30 m2 The answer is (B).


question: In an office, 50 percent of the workers have at least 5 years of service, and a total of 16 workers have at least 10 years of service. If 90 percent of the workers have fewer than 10 years of service, how many of the workers have at least 5 but fewer than 10 years of service?
Options:
(A)  8
(B)  64
(C)  50
(D)  144
(E)  160
answer: Stream of consciousness: (10/100)Workers = 16 = > number of workers = 160
(50/100)*Workers = x+16 = > x = 8 The answer is (A).


question: Two pipes A and B can fill a cistern in 20 and 30 minutes respectively, and a third pipe C can empty it in 40 minutes. How long will it take to fill the cistern if all the three are opened at the same time?
Options:
(A) 17 1/4 min
(B) 28 1/7 min
(C) 17 1/7 min
(D) 17 1/8 min
(E) 17 5/7 min
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: 1/20 + 1/30 - 1/40 = 7/120
120/7 = 17 1/7 The answer is (C).