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?

Correct option is A

Given:

Side of square field = 19 m

Speed = 2 km/h

Formula Used:

Perimeter of square = 4 × side

Time = $$\frac{\text{Distance}} {\text{ Speed}}$$​​

Solution:

Perimeter of square field = 4 × 19 = 76 m

Speed in m/s = $$\frac{2 \times 1000}{3600} = \frac{2000}{3600} = \frac{5}{9} m/s$$​​

Time = $$\frac{76}{5/9} = 76 \times \frac{9}{5}$$​​

$$= \frac{684}{5}$$​ = 136.8 seconds

Thus, The boy will take 136.8 seconds to complete one round