question: Two trains are moving at 50 kmph and 70 kmph in opposite directions. Their lengths are 150 m and 100 m respectively. The time they will take to pass each other completely is?
Options:
(A) 7 1/7 sec
(B) 7 7/2 sec
(C) 7 1/8 sec
(D) 7 1/2 sec
(E) 7 3/2 sec
answer: Stream of consciousness: 70 + 50 = 120 * 5/18 = 100/3 mps
D = 150 + 100 = 250 m
T = 250 * 3/100 = 15/2 = 7 1/2 sec The answer is (D).

q: Find a a prime number from the options below.
Options:
(A) 37
(B) 38
(C) 39
(D) 40
(E) 42
a: Stream of consciousness: Clearly, 37 is a prime number. The answer is (A).

question: Calculate the value of n from the below equation: n^310n+20=44
Options:
(A) 1
(B) 5
(C) 3
(D) 2
(E) 4
answer: Stream of consciousness: Use elimination method to find the correct option. you find that of all the options when 4 is the correct value for n The answer is (E).

q: The speed of a train is 90 kmph. What is the distance covered by it in 10 minutes?
Options:
(A) 15
(B) 17
(C) 19
(D) 10
(E) 12
a: Stream of consciousness: 90 * 10/60 = 15 kmph The answer is (A).

question: A man rows his boat 120 km downstream and 60 km upstream, taking 2 hours each time. Find the speed of the stream?
Options:
(A) 6
(B) 15
(C) 17
(D) 18
(E) 2
answer: Stream of consciousness: Speed downstream = d/t = 120/(2 ) = 60 kmph
Speed upstream = d/t = 60/(2) = 30 kmph
The speed of the stream = (60 - 30)/2 = 15 kmph The answer is (B).

question: The compound ratio of 2/3, 6/7, 4/3 and 1/8 is given by?
Options:
(A) 2/21
(B) 1/48
(C) 1/98
(D) 1/96
(E) 1/68
answer:
Stream of consciousness: 2/3 * 6/7 * 4/3 * 1/8 = 48/504 = 2/21 The answer is (A).