q: If a man can cover 16 metres in one second, how many kilometres can he cover in 3 hours 45 minutes?
Options:
(A) 180km
(B) 190km
(C) 200km
(D) 210km
(E) 216km
a: 16 m/s = 16 * 18/5 kmph
3 hours 45 minutes = 3 3/4 hours = 15/4 hours
Distance = speed * time = 16 * 18/5 * 15/4 km = 216 km. The answer is (E).
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q: A car has a 20-gallon fuel to travel 500 miles.At this rate, how many gallons of fuel are needed for a 1000 mile car ?
Options:
(A) 10
(B) 30
(C) 20
(D) 40
(E) 50
a: Number of gallons of fuel per mile = 500 /20 = 25 gallons per mile
Number of gallons of fuel for a 1000 mile car = 1000/25 = 40 The answer is (D).
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q: If 1/2 of the air in a tank is removed with each stroke of a vacuum pump, what fraction of the original amount of air has been removed after 5 strokes ?
Options:
(A) 31/32
(B) 7/8
(C) 1/4
(D) 1/8
(E) 1/16
a: Left After 1st stroke = 1/2
Left After 2nd stroke = 1/2 * 1/2 = 1/4
Left After 3rd stroke = 1/2 * 1/4 = 1/8
Left After 4th stroke = 1/2 * 1/8 = 1/16
Left After 5th stroke = 1/2 * 1/16 = 1/32
So removed = 1- 1/32 = 31/32 The answer is (A).
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q: A car traveled from San Diego to San Francisco at an average speed of 51 miles per hour. If the journey back took twice as long, what was the average speed of the trip?
Options:
(A) 24.
(B) 34.
(C) 36.
(D) 42.
(E) 44.
a:
Let the time taken be = x
One way distance = 51x
Total distance traveled = 2 * 51x = 102x
Total time taken = x + 2x = 3x
Average speed = 102x/3x = 34 The answer is (B).
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