The area of a square field is 400 km2. How long will it take for a horse to run around at the speed of 20 km/h ?	Select the correct option:
A) 12 h
B) 10 h
C) 4 h
D) 6 h
E) None of these
Explanation Area of field = 400 km2. Then, each side of field = √400=20km Distance covered by the horse = Perimeter of square field = 20 × 4 = 80 km ∴ Time taken by horse = distances/peed=80/20= 
<gadget id="calculator">80/20</gadget>
<output>4</output>
4h Answer 4 h
<result>C</result>
The area of a square field is 400 km2. How long will it take for a horse to run around at the speed of 20 km/h ?