Q: A train running at the speed of 60 km/hr crosses a pole in 9 seconds. Find the length of the train.
Options:
(A) 150 m
(B) 145 m
(C) 140 m
(D) 135 m
(E) 155 m
A: OK... Stream of consciousness: Speed = 60*(5/18) m/sec = 50/3 m/sec
Length of Train (Distance) = Speed * Time
(50/3) * 9 = 150 meter
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) 29 Years
(B) 32 Years
(C) 37 Years
(D) 49 Years
(E) 50 Years
A: OK... 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 (D).

Q: An analyst will recommend a combination of 3 industrial stocks, 2 transportation stocks, and 2 utility stocks. If the analyst can choose from 5 industrial stocks, 4 transportation stocks, and 4 utility stocks, how many different combinations of 7 stocks are possible?
--
Options:
(A) 12
(B) 360
(C) 60
(D) 180
(E) 720
A: OK... Stream of consciousness: 5C3 * 4C2 * 4C2 = 10*6*6 = 360.
The answer is (B).

Q: What should come in place of question mark(?) in the following equation?
8597 ? = 7429 4358
Options:
(A) 5706
(B) 5526
(C) 5426
(D) 5626
(E) None of these
A:
OK... Stream of consciousness: 8597 ? = 7429 4358
? = 5526
The answer is (B).