q: A and B can do a work in 12 days, B and C in 30 days and C and A in 36 days. In how many days will the work be completed, if all three of them work together?
Options:
(A) 180/18
(B) 180/15
(C) 180/13
(D) 180/12
(E) 180/11
a: Stream of consciousness: One day work of A and B = 1/12
One day work of B and C = 1/30
One day work of C and A = 1/36
2(A + B + C) = 1/12 + 1/30 + 1/36
2(A + B + C) = 13/90
(A + B + C) = 13/180
Number of days required = 180/13 days. The answer is (C).

question: From a Group of 9 People, Including George and Nina, 4 people are to be selected at random to work on a certain project. What is the probability that 4 people selected will include George but not Nina
Options:
(A) 5/56
(B) 9/56
(C) 15/56
(D) 35/120
(E) 25/56
answer: Stream of consciousness: Number of ways of selecting 4 people out of 9 people = 9C4
In the three members George will always be there in the team. At this step we have vacancy for 3 more members and 8 members are available. Nina cannot be there in the team. So 3 members have to be selected and the number of available members = 8 - Nina = 7
Number of ways to form a 4 member team that includes George and excludes Nina = 7C3
Probability = 7C3/9C4 = 35/120 The answer is (D).

q: A 600 meter long train crosses a signal post in 20 seconds. How long will it take to cross a 3 kilometer long bridge, at the same speed?
Options:
(A) 4 min
(B) 2 min
(C) 8 min
(D) 9 min
(E) 5 min
a: Stream of consciousness: S = 600/20 = 1530 mps
S = 3600/30 = 120 sec = 2 min The answer is (B).

question: CMM, EOO, GQQ, _____, KUU
Options:
(A) MSQ
(B) IPS
(C) IIS
(D) ISS
(E) POL
answer: Stream of consciousness: The first letters are in alphabetical order with a letter skipped in between each segment: C, E, G, I, K. The second and third letters are repeated; they are also in order with a skipped letter: M, O, Q, S, U. The answer is (D).

q: If X and Y are both positive two-digit integers and share no digits, and X > Y, what is the smallest possible value of X - Y?
Options:
(A) 0
(B) 1
(C) 2
(D) 3
(E) 9
a: Stream of consciousness: Answer = B = 1
20 - 19 = 30-29 = 40-39 = 50-49 = 1 The answer is (B).

q: A man took loan from a bank at the rate of 12% p.a. simple interest. After 3 years he had to pay Rs. 5400 interest only for the period. The principal amount borrowed by him was.
Options:
(A) 15000
(B) 2655
(C) 16888
(D) 6677
(E) 1871
a:
Stream of consciousness: Principal = Rs. (100 x 5400)/(12*3) = Rs. 15000. The answer is (A).