How many seconds will a boy take to run one complete round around a square field of side 19 metres, if he runs at a speed of 2 km/h?A136.8B141C144D138Answer: A. 136.8 Read Explanation: Side of Square a=19ma = 19 ma=19mPerimeter of field =4a=4a=4a=4×19=76m=4\times{19}=76m=4×19=76mSpeed=2km/hSpeed = 2km/hSpeed=2km/h=2×518=59= 2\times{\frac{5}{18}}=\frac{5}{9}=2×185=95m/sTime Taken =7659= \frac{76}{\frac{5}{9}}=9576=136.8sec=136.8 sec=136.8sec Read more in App