How long will a boy take to run round a square field of side 50 meters, if he runs at the rate of 10km/hr?	Pick one
A) 52sec B) 45sec C) 72sec D) 25sec E) 39sec
Speed = 10 km/hr = 10*5/18 = 25/9 m/sec   Distance = 50*4= 
<gadget id="calculator">50*4</gadget>
<output>200</output>
200m   Time taken= 200*9/25= 
<gadget id="calculator">200*9/25</gadget>
<output>72</output>
72sec   Answer is 72sec
<result>C</result>
How long will a boy take to run round a square field of side 50 meters, if he runs at the rate of 10km/hr?