How long will a boy take to run round a square field of side 40 meters, if he runs at the rate of 9km/hr?	Choose the correct choice from the following options.
A) 64sec B) 45sec C) 1min D) 32sec E) 25sec
Speed = 9 km/hr = 9*5/18 = 5/2 m/sec   Distance = 40*4= 
<gadget id="calculator">40*4</gadget>
<output>160</output>
160m   Time taken= 160*2/5= 
<gadget id="calculator">160*2/5</gadget>
<output>64</output>
64sec   64secnswer is 64sec
<result>A</result>
How long will a boy take to run round a square field of side 40 meters, if he runs at the rate of 9km/hr?