M4maths Previous Puzzles

28 Nov 2019 Distance-Speed

The speed of a car is 63 km/h if we don’t let it stop at any point. If the car stops at stops, the speed of the car is 54 km/h. What is the time in minutes that the car stops for per hour?

OPtion

1) 12.00
2) 8.00
3) 10.00
4) 16.00
5) 13.00
6) 7.57
7) 8.57
8) 9.12
9) 11.20
10) None of these

Solution

Distance = Speed × Time.
As the speed of the car is 63 km/h, it will cover 63 km in one hour. Similarly, when we let the car stop, it will cover 54 km/h. Therefore, due to stoppages, it covers 9 km lesser.
Time taken to cover 9 km = [(Distance/Speed)] = [(9/63)] h = (9/63)×60 min = 60/7 min = 8.57 min

Correct Option: 7 Best Solution (1)

SAYAN CHATTERJEE   5 years AGO

In 1 hr, the car Losses (63-54)= 9 km
so, 9 km would take 9/63*60= 8.57 mins.
Option 7.

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