A and B take part in a 500 m race. A runs at 24 km per hour. A gives B a start of 40 m and still bea

M4maths Previous Puzzles

21 Jul 2022 Time Distance & Speed

A and B take part in a 500 m race. A runs at 24 km per hour. A gives B a start of 40 m and still beats him by 15 seconds. The speed of B is

OPtion

1) 15.5 km/hr
2) 16.4 km/hr
3) 14.5 km/hr
4) 16.8 km/hr
5) 18.4 km/hr
6) 15.2 km/hr
7) 20.5 km/hr
8) 17.4 km/hr
9) 15.8 km/hr
10) None of these

Solution

A's speed = 24 x (5/18) m/s = 20/3 m/s
Time taken by A to cover 500 m = 500/(20/3) = 75 sec
.'. Time taken by B to cover 460 m = (75+15) = 90 sec.
Hence, B's speed = (460/90) x (18/5) = 92/5 m/s = 18.4 km/h
Correct Option 5)

Correct Option: 5 Best Solution (2)