Reasoning: 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 = 15 * 20 = 300 = Length of train
Length of platform = 600 - 300 = 300
Ans: (C)
Question: A train traveling at 72 kmph crosses a platform in 30 seconds and a man standing on the platform in 15 seconds. What is the length of the platform in meters?
Options:
(A) 240 meters
(B) 360 meters
(C) 300 meters
(D) 600 meters
(E) Cannot be determined
Rationale: 44 + 28 + 10 = 82%
100 82 = 18%
650 * 18/100 = 117
The answer: (E)
Question: In a school of 650 boys, 44% of Muslims, 28% Hindus, 10% Sikhs and the remaining of other communities. How many belonged to the other communities?
Options:
(A) 173
(B) 163
(C) 153
(D) 143
(E) 117
Reasoning: Part filled by (A + B + C) in 3 minutes = 3(1/30 + 1/20 + 1/10) = 11/20
Part filled by B in 3 minutes = 3/20
Required ratio = 3/20 * 20/11 = 3/11
Ans: (C)
Question: Three pipes A, B and C can fill a tank from empty to full in 30 minutes, 20 minutes and 10 minutes respectively. When the tank is empty, all the three pipes are opened. A, B and C discharge chemical solutions P, Q and R respectively. What is the proportion of solution Q in the liquid in the tank after 3 minutes?
Options:
(A) 1/11
(B) 2/11
(C) 3/11
(D) 4/11
(E) 5/11
Rationale: Age of B = Age of (A + B + C) Age of (A + C) = 29 3 32 2 = 87 64 = 23 years
The answer: (E)
Question: The average age of A, B and C is 29 years. If the average age of A and C is 32 years, what is the age of B in years ?
Options:
(A) 19
(B) 35
(C) 20
(D) 32
(E) 23
Reasoning: P = (P*3*R)/100
R = 33 1/3%
Ans: (B)
Question: In what time a sum of money double itself at 3% per annum simple interest?
Options:
(A) 33 1/7%
(B) 33 1/3%
(C) 33 1/2%
(D) 33 7/3%
(E) 33 5/3%
Reasoning: A perfect square will never end in 2, 3, 7 or 8. (last digit cannot be 2, 3, 7 or 8)
Here E is the odd one out.
Ans: (E)
Question: If x is a positive integer, which of the following could NOT be the square of x?
Options:
(A) 5,008,644
(B) 5,004,169
(C) 4,999,696
(D) 4,995,225
(E) 4,990,752