A and B take part in a 200 m race. A run at 5.4 Km/h. A gives B a start of 12 m and still beat him b

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25 Nov 2021 Speed

A and B take part in a 200 m race. A run at 5.4 Km/h. A gives B a start of 12 m and still beat him by 6 sec. Speed of B is:

OPtion

1. 5.15 Km/h
2. 4.14 Km/h
3. 4.25 Km/h
4. 4.40 Km/h
5. 4.51 Km/h
6. 5.20 Km/h
7. 4.85 Km/h
8. 4.95 Km/h
9. 5.11 Km/h
10. None of the above

Solution

A’s speed = (5.4x 5/18) m/sec = 27/18 m/sec
Time taken by A to cover 200 m
= (200 x 18/27) sec = 133.33 seconds.
∴ B covers 188 m in 133.33 + 6 = 139.33 seconds.
B’s speed = {(188/139.33) x (18/5)} Km/h
= 4.85 Km/h

Correct Option: 7 Best Solution (0)