q: A train 150 m long running at 72 kmph crosses a platform in 25 sec. What is the length of the platform?
Options:
(A) 33
(B) 87
(C) 350
(D) 88
(E) 277
a: Stream of consciousness: D = 72 * 5/18 = 25 = 500 150 = 350 The answer is (C).

question: 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) 155 m
(C) 180 m
(D) 190 m
(E) 205 m
answer: Stream of consciousness: Answer: Option A
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 of nine numbers is 17. The average of first four numbers is 20 and the average of last four numbers is 16. What is the middle number?
Options:
(A) A) 7
(B) B) 8
(C) C) 9
(D) D) 10
(E) E) 11
a: Stream of consciousness: The total of nine numbers = 9X17 = 153
The total of first 4 and last 4 numbers is = 4 X 20+4 X 16 = 144
So, the middle number is (153 - 144 ) = 9 The answer is (C).

question: The average mark obtained by 22 candidates in an examination is 48. The average of the first ten is 55 while the last eleven is 40 .The marks obtained by the 11th candidate is ?
Options:
(A) 22
(B) 0
(C) 49
(D) 58
(E) 66
answer: Stream of consciousness: It is clear that 22 x 48 = 10 x 55 + K + 11 x 40 K = 66 The answer is (E).

q: Four of the five parts numbered (a), (b), (c), (d) and (e) in the following equation are exactly equal. Which of the parts is not equal to the other four? The number of that part is the answer.
Options:
(A) 371.587 + 46.32 217.907
(B) 4 125 75 4
(C) 58.25 4.5 65.875
(D) 25 12 2 5 10
(E) 121 3.5 2 111.75
a: Stream of consciousness: The other parts are equal to 200. The answer is (C).

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) 45 Years
(B) 46 Years
(C) 49 Years
(D) 52 Years
(E) 54 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 (C).