question: 10 books are placed at random in a shelf. The probability that a pair of books will always be together is
Options:
(A) 1/6
(B) 1/9
(C) 1/5
(D) 1/6
(E) 1/3
answer: Stream of consciousness: 10 books can be rearranged in 10! ways consider the two books taken as a pair then number of favourable ways of getting these two books together is 9! 2!
Required probability = 1/5 The answer is (C).

q: A train running at the speed of 60 km/hr crosses a pole in 6 sec. What is the length of the train?
Options:
(A) 120 m
(B) 100 m
(C) 324 m
(D) Cannot be determined
(E) None of these
a: Stream of consciousness: Speed = 60* 5/18 = 50/3 m/sec
Length of the train = speed * time = 50/3 * 6 = 100 m The answer is (B).

question: A can do a piece of work in 6 hours; B and C together can do it in 4 hours, which A and C together can do it in 3 hours. How long will B alone take to do it?
Options:
(A) 8hours
(B) 6hours
(C) 14hours
(D) 12hours
(E) 5hours
answer: Stream of consciousness: A's 1 hour work = 1/6;
(B + C)'s 1 hour work = 1/4;
(A + C)'s 1 hour work = 1/3
(A + B + C)'s 1 hour work = (1/4 + 1/6) = 5/12
B's 1 hour work = (5/12 - 1/3) = 1/12
B alone will take 12 hours to do the work. The answer is (D).

q: If f(x)=1/x and x is a natural number, what CANNOT be the answer for f(f(x))?
Options:
(A) 1/7
(B) 3
(C) 12/3
(D) 6/6
(E) 1
a: Stream of consciousness: Answer A is impossible because the invers of 1/x is x, and the only way to have something other than a natural number is to input something other than a natural number. With the specification that only natural numbers may be used 1/7 is not a possibility for f(f(x)) The answer is (A).

question: What percent is 36 paisa's of 12 rupees?
Options:
(A) 2 %
(B) 3 %
(C) 4 %
(D) 5 %
(E) 6 %
answer: Stream of consciousness: 12 Rupees = 1200 paisa's
36/1200 100 = 3/12
12/3 = 3 % The answer is (B).

question: 30 pens and 75 pencils were purchased for 510. If the average price of a pencil was 2.00, find the average price of a pen.
Options:
(A) 10
(B) 11
(C) 12
(D) 13
(E) 14
answer:
Stream of consciousness: Since average price of a pencil = 2
Price of 75 pencils = 150
Price of 30 pens = (510 150) = 360
Average price of a pen = 36060 = 12 The answer is (C).