q: A can do a certain work in 12 days. B is 60% more efficient than A. How many days does B alone take to do the same job ?
Options:
(A) 19
(B) 15
(C) 16
(D) 17
(E) 18
a: Stream of consciousness: Ratio of time taken by A & B = 160:100 = 8:5 Suppose B alone takes x days to do the job. Then, 8:5::12:x = > 8x = 5*12 = > x = 15 days. The answer is (B).

question: 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
answer: 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).

q: The average age of a class of 32 students is 16 yrs. if the teacher's age is also included, the average increases by one year. Find the age of the teacher
Options:
(A) 28 Years
(B) 30 Years
(C) 32 Years
(D) 37 Years
(E) 49 Years
a: Stream of consciousness: Total age of students is 32X16 = 512 Years
Total age inclusive of teacher = 33X (16+1) = 561
So, Teacher's age is 561-512 = 49 Yrs
There is a shortcut for these type of problems
Teacher's age is 16+(33X1) = 49 Years The answer is (E).

question: In what time a sum of money double itself at 6% per annum simple interest?
Options:
(A) 33 1/8%
(B) 33 1/3%
(C) 83 1/3%
(D) 33 4/3%
(E) 16 2/3%
answer: Stream of consciousness: P = (P*6*R)/100
R = 16 2/3% The answer is (E).

q: A train of 24 carriages, each of 60 meters length, when an engine also of 60 meters length is running at a speed of 60 kmph. In what time will the train cross a bridge 1.5 km long?
Options:
(A) 2 mins
(B) 3 mins
(C) 9 mins
(D) 8 mins
(E) 6 mins
a: Stream of consciousness: D = 25 * 60 + 1500 = 3000 m
T = 3000/60 * 18/5 = 180 sec = 3 mins The answer is (B).

q: If 4 men can colour 48 m long cloth in 2 days, then 6 men can colour 36 m long cloth in
Options:
(A) 1 day
(B) 2 days
(C) 3 days
(D) 4 days
(E) 5 days
a:
Stream of consciousness: The length of cloth painted by one man in one day = 48 / 4 2 = 6 m
No. of days required to paint 36 m cloth by 6 men = 36/ 6 6 = 1 day. The answer is (A).