How long will a boy take to run round a square field of side 50 meters, if he runs at the rate of 9km/hr? Choose the correct choice from the following options
A) 80sec
B) 45sec
C) 1min
D) 32sec
E) 25sec
Speed = 9 km/hr = 9*5/18 = 5/2 m/sec   Distance = 50*4= 
<gadget id="calculator">50*4</gadget>
<output>200</output>
200m   Time taken= 200*2/5= 
<gadget id="calculator">200*2/5</gadget>
<output>80</output>
80sec   80secnswer is 80sec
<result>A</result>
How long will a boy take to run round a square field of side 50 meters, if he runs at the rate of 9km/hr?