Question

18. How long will a boy take to run round a square field of side 35 metres, if he runs at the rate of
9 km/hr?
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Answer 1

56Sec

The perimeter of the square field of 35 m sides is 140 m.

The boy’s running rate is 9km/hr = 9000 m/60 min = 150 m/min

So the boy will take 140*60/150 = 56 secs to run round the field

Thanks

Answer 2

Speed = 9 km/hr = 9 x (5/18) m/sec = 5/2 m/sec

Distance = (35 x 4) m = 140 m.

Time taken = 140 x (2/5) sec= 56 sec