question: A can do a piece of work in 4 hours; B and C together can do it in 3 hours, which A and C together can do it in 2 hours. How long will B alone take to do it?
Options:
(A) 15 hours
(B) 14 hours
(C) 12 hours
(D) 74 hours
(E) 79 hours
answer: Stream of consciousness: A's 1 hour work = 1/4;
(B + C)'s 1 hour work = 1/3;
(A + C)'s 1 hour work = 1/2
(A + B + C)'s 1 hour work = (1/4 + 1/3) = 7/12
B's 1 hour work = (7/12 + 1/2) = 1/12
B alone will take 12 hours to do the work. The answer is (C).


q: A Train requires 10 seconds to pass a pole while it requires 40 seconds to cross a stationary train which is 300 mtrs long. Find the speed of the train.
Options:
(A) 36kmph
(B) 42kmph
(C) 48kmph
(D) 52kmph
(E) 64kmph
a: Stream of consciousness: In 10s the train crosses the pole and in 40 sec the train crosses one more stationary train
In 30 sec the train travels a distance of 300 mtrs
Speed = 300/30 = 10 m/s = 10 * 18/5 = 36 kmph The answer is (A).


question: If x is an odd integer, which of the following is an odd integer?
Options:
(A) 2x+2
(B) x^2
(C) 2x+4x
(D) 1+2x+x^2
(E) 3x-1
answer: Stream of consciousness: Plug in an odd integer; in this case 3
(2*3)+2 = 8 Even
3^2 = 9 Odd
(2*3)+(4*3) = 6 + 12 = 18 Even
1+(2*3)+3^2 = 1+ 6 + 9 = 16 Even
(3*3)-1 = 9 - 1 = 8 Even The answer is (B).


q: A pipe can fill a cistern in 7 minutes whereas the cistern when fill can be emptied by a leak in 14 minutes. When both pipes are opened, find when the cistern will be full?
Options:
(A) 17
(B) 16
(C) 70
(D) 14
(E) 12
a: Stream of consciousness: 1/7 - 1/14 = 1/14
14 minutes The answer is (D).


question: If a man can cover 14 metres in one second, how many kilometres can he cover in 3 hours 45 minutes?
Options:
(A) 288
(B) 162
(C) 189
(D) 168
(E) 122
answer: Stream of consciousness: 14 m/s = 14 * 18/5 kmph
3 hours 45 minutes = 3 3/4 hours = 15/4 hours
Distance = speed * time = 14 * 18/5 * 15/4 km = 189 km. The answer is (C).


question: The average mark obtained by 22 candidates in an examination is 48. The average of the first ten is 55 while the last eleven is 40 .The marks obtained by the 11th candidate is ?
Options:
(A) 22
(B) 0
(C) 49
(D) 58
(E) 66
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: It is clear that 22 x 48 = 10 x 55 + K + 11 x 40 ⇒⇒ K = 66 The answer is (E).