Rationale: 20 + 24 + 8 * 2 = 60/2 = 30
The answer: (C)
Question: The average age of 8 men increases by 2 years when two women are included in place of two men of ages 20 and 24 years. Find the average age of the women?
Options:
(A) 11
(B) 12
(C) 30
(D) 98
(E) 15
Reasoning: In 10s the train crosses the pole and in 30 sec the train crosses one more stationary train
In 20 sec the train travels a distance of 600 mtrs
Speed = 600/20 = 30 m/s = 30 (3600/1000) = 30 * 18/5 = 108 kmph
Ans: (C)
Question: A Train requires 10 seconds to pass a pole while it requires 30 seconds to cross a stationary train which is 600 mtrs long. Find the speed of the train.
Options:
(A) 110 kmph
(B) 120 kmph
(C) 108 kmph
(D) 100 kmph
(E) 98 kmph
Rationale: Work done by P in 1 day = 1/20
Work done by Q in 1 day = 1/12
Work done by P in 4 days = 4 (1/20) = 1/5
Remaining work = 1 1/5 = 4/5
Work done by P and Q in 1 day = 1/20 + 1/12 = 8/60 = 2/15
Number of days P and Q take to complete the remaining work = (4/5) / (2/15) = 6
Total days = 4 + 6 = 10
The answer: (E)
Question: P and Q can complete a work in 20 days and 12 days respectively. P alone started the work and Q joined him after 4 days till the completion of the work. How long did the work last?
Options:
(A) 5 days
(B) 9 days
(C) 30 days
(D) 20 days
(E) 10 days
Reasoning: Percentage of profit = 35/15 * 100 = 233%
Ans: (E)
Question: If the cost price of 50 articles is equal to the selling price of 15 articles, then the gain or loss percent is?
Options:
(A) 16
(B) 127
(C) 12
(D) 18
(E) 233
Rationale: S = 250/12 * 18/5 = 75kmph
The answer: (D)
Question: A 250 meter long train crosses a man standing on the platform in 12 sec. What is the speed of the train?
Options:
(A) 228
(B) 108
(C) 1266
(D) 75
(E) 211
Rationale: Equation: 500/r = 500/(r+50) + 1
Plug options into the equation
A fits: 500/250 = 500/(250+250) + 1
The answer: (A)
Question: A plane flies 500 miles at a speed of r mph. If the plane flies at a speed of r + 250 miles per hour, it would fly the same distance in 1 hour less. What is the value of r?
Options:
(A) 250 mph
(B) 200 mph
(C) 205 mph
(D) 300 mph
(E) 425 mph