question: The average age of a class of 40 students is 15 yrs. if the teacher's age is also included, the average increases by one year. Find the age of the teacher
Options:
(A) 30 Years
(B) 56 Years
(C) 32 Years
(D) 34 Years
(E) 49 Years
answer: Stream of consciousness: Total age of students is 40X15 = 600 Years
Total age inclusive of teacher = 41X (15+1) = 656
So, Teacher's age is 656-600 = 56 Yrs
There is a shortcut for these type of problems
Teacher's age is 15+(41X1) = 56 Years The answer is (B).

q: Anil can do a work in 12 days while Sunil can do it in 25 days. How long will they take if both work together?
Options:
(A) 10 1/10 days
(B) 18 1/10 days
(C) 7 1/10 days
(D) 8 1/10 days
(E) 9 1/10 days
a: Stream of consciousness: 1/12 + 1/25 = 37/300
300/37 = 8 1/10 days The answer is (D).

question: John left home and drove at the rate of 45 mph for 2 hours. He stopped for lunch then drove for another 3 hours at the rate of 55 mph to reach his destination. How many miles did John drive?
Options:
(A) 235 miles.
(B) 245 miles.
(C) 255 miles.
(D) 265 miles.
(E) 275 miles.
answer: Stream of consciousness: The total distance D traveled by John is given by
D = 45 * 2 + 3 * 55 = 255 miles. The answer is (C).

q: A tyre has two punctures. The first puncture along would have made the tyre flat in 9 minutes and the second alone would have done it in 6 minutes. If air leaks out at a constant rate, how long does it take both the punctures together to make it flat?
Options:
(A) 1 12 minutes
(B) 3 12 minutes
(C) 3 35 minutes
(D) 4 14 minutes
(E) None of these
a: Stream of consciousness: 1 minute's work of both the punctures = (19 + 16) = 518
So, both the punctures will make the tyre flat in 185 = 335 min. The answer is (C).

question: Find the value of y from (12)^3 x 6^4 432 = y?
Options:
(A) 6434
(B) 4673
(C) 7684
(D) 7658
(E) 5184
answer: Stream of consciousness: Given Exp. = (12)3 x 64 = (12)3 x 64 = (12)2 x 62 = (72)2 = 5184
432 12 x 62 The answer is (E).

question: The compound ratio of 2/3, 6/7, 1/3 and 3/8 is given by?
Options:
(A) 7/98
(B) 1/48
(C) 1/98
(D) 1/96
(E) 3/42
answer:
Stream of consciousness: 2/3 * 6/7 * 1/3 * 3/8 = 36/504 = 3/42 The answer is (E).