Question: A man rows his boat 84 km downstream and 48 km upstream, taking 2 hours each time. Find the speed of the stream?
Options:
(A) 6 kmph
(B) 5 kmph
(C) 9 kmph
(D) 8 kmph
(E) 1 kmph
Answer: Speed downstream = d/t = 84/(2) = 42 kmph
Speed upstream = d/t = 48/(2) = 24 kmph
The speed of the stream = (42 - 24)/2 = 9 kmph
The answer is (C).

Question: If, when the two parties of knights encounter one another after a month, exactly one knight changes from one travelling party to the other travelling party, that knight must be
Options:
(A) P
(B) Q
(C) R
(D) S
(E) T
Answer: Q because Q always have to travel in northern route
The answer is (B).

Question: A train traveling at 72 kmph crosses a platform in 30 seconds and a man standing on the platform in 19 seconds. What is the length of the platform in meters?
Options:
(A) 220 meters
(B) 360 meters
(C) 420 meters
(D) 600 meters
(E) Cannot be determined
Answer: Speed of the train in metres/sec = 72000/3600 = 20
Distance travelled by train to cross the platform = 30 * 20 = 600 = Length of train + Length of platform
Distance travelled by train to cross the man = 19 * 20 = 380 = Length of train
Length of platform = 600 - 380 = 220
The answer is (A).

Question: Solve below question 2x - 1 = 17
Options:
(A) -8
(B) -9
(C) -5
(D) -4
(E) 9
Answer:
1. Add 1 to both sides: 2x - 1 + 1 = 17 + 1 2. Simplify both sides: 2x = 18 3. Divide both sides by 2: 4. Simplify both sides: x = 9
The answer is (E).