q: A and B together can complete a work in 12 days. A alone can complete it in 20 days. If B does the work only for half a day daily, then in how many days A and B together will complete the work?
Options:
(A) 11 days
(B) 77 days
(C) 15 days
(D) 18 days
(E) 19 days
a: Stream of consciousness: B's 1 day work = (1/12 - 1/20) = 1/30
Now, (A + B)'s 1 day work = (1/20 + 1/60) = 1/15
So, A and B together will complete the work in 15 days. The answer is (C).

question: If a man can cover 20 metres in one second, how many kilometres can he cover in 3 hours 45 minutes?
Options:
(A) 288
(B) 162
(C) 220
(D) 270
(E) 122
answer: Stream of consciousness: 20 m/s = 20 * 18/5 kmph
3 hours 45 minutes = 3 3/4 hours = 15/4 hours
Distance = speed * time = 20 * 18/5 * 15/4 km = 270 km. The answer is (D).

q: Rs.600 amounts to Rs.900 in 3 years at simple interest. If the interest is increased by 4%, it would amount to how much?
Options:
(A) 672
(B) 246
(C) 258
(D) 856
(E) 653
a: Stream of consciousness: (600*3*4)/100 = 72
600 + 72 = 672 The answer is (A).

question: A 120 meter long train crosses a man standing on the platform in 6 sec. What is the speed of the train?
Options:
(A) 229
(B) 108
(C) 278
(D) 72
(E) 112
answer: Stream of consciousness: S = 120/6 * 18/5 = 72 kmph The answer is (D).

q: Sumitra has an average of 56% on her first 7 examinations. How much should she make on her eighth examination to obtain an average of 60% on 8 examinations?
Options:
(A) 88%
(B) 78%
(C) 98%
(D) Cannot be determined
(E) None of these
a: Stream of consciousness: Since the weight age of eighth examination is not known, hence can not be determine The answer is (D).

q: A 600 meter long train crosses a signal post in 40 seconds. How long will it take to cross a 3 kilometer long bridge, at the same speed?
Options:
(A) 4 min
(B) 5 min
(C) 6 min
(D) 8 min
(E) 10 min
a:
Stream of consciousness: S = 600/40 = 15 mps
S = 3600/15 = 240 sec = 4 min The answer is (A).