Mathematics Mcqs

A man goes to his office from his house at a speed of 3 km/hr and returns at a speed of 2 km/hr. If he takes 5 hours in going and coming, what is the distance between his house and office?

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A man goes to his office from his house at a speed of 3 km/hr and returns at a speed of 2 km/hr. If he takes 5 hours in going and coming, what is the distance between his house and office?

A. 3 km
B. 4 km
C. 5 km
D. 6 km

A man covers a distance of 20 km in 3.5 hours partly by running and partly by walking. If he walks at 4 kmph and runs at 10 kmph, find the distance he covers by walking.

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A man covers a distance of 20 km in 3.5 hours partly by running and partly by walking. If he walks at 4 kmph and runs at 10 kmph, find the distance he covers by walking.

A. 10 km
B. 8 km
C. 12 km
D. 9 km

Let the distance covered by walking be x km
the distance covered by running be (20-x) km Time for walking + time for running = 3.5 hours (x/4)+[(20-x)/10]=3.5 Solving,
5x+40-2x = 70
3x=30
x=10km

Two bikes start at the same time from two destination 300 km apart and travel towards each other. If they cross each other at a distance of 130 km from one of the destination, what is the ratio of their speeds?

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Two bikes start at the same time from two destination 300 km apart and travel towards each other. If they cross each other at a distance of 130 km from one of the destination, what is the ratio of their speeds?

A. 17:13
B. 17:30
C. 13:30
D. None of these

Walking 6/7th of his usual speed, a man is 12 minutes too late. What is the usual time taken by him to cover that distance?

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Walking 6/7th of his usual speed, a man is 12 minutes too late. What is the usual time taken by him to cover that distance?

A. 1 hr 42 min
B. 1 hr
C. 2 hr
D. 1 hr 12 min
New speed = 6/7 of usual speed
Speed and time are inversely proportional.
Hence new time = 7/6 of usual time
Hence, 7/6 of usual time – usual time = 12 minutes
=> 1/6 of usual time = 12 minutes
=> usual time = 12 x 6 = 72 minutes
= 1 hour 12 minutes

Excluding stoppages, the speed of a bus is 54 kmph and including stoppages, it is 45 kmph. For how many minutes does the bus stop per hour?

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Excluding stoppages, the speed of a bus is 54 kmph and including stoppages, it is 45 kmph. For how many minutes does the bus stop per hour?

A. 12
B. 11
C. 10
D. 9
speed of the bus excluding stoppages = 54 kmph
speed of the bus including stoppages = 45 kmph
Loss in speed when including stoppages = 54 – 45 = 9kmph
=> In 1 hour, bus covers 9 km less due to stoppages
Hence, time that the bus stop per hour = time taken to cover 9 km
=distance/speed=9/54 hour=1/6 hour = 60/6 min=10 min

There are 21 poles with a constant distance between each pole. A car takes 30 seconds to reach the 16th pole. How long does it take to reach the last pole?

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There are 21 poles with a constant distance between each pole. A car takes 30 seconds to reach the 16th pole. How long does it take to reach the last pole?

A. 39 seconds
B. 40 seconds
C. 39.38 seconds
D. 39.5 seconds
The first pole is crossed at the zeroth second. The timer starts after the car crosses the first pole. Let the distance between each pole be x m. To reach the 16th pole, the distance travelled by the car is 15x. The speed of the car is 15x/30 = x/2 m/s To reach the 21st pole, it has to travel a distance of 20x. Time taken
= 20x÷(x/2)
= 40 seconds