## How many minutes does Ashok take to cover a distance of 400 meters if he runs at a speed of 20 km/hr ?

Ashok’s speed = 20 km/hr = $(20\times \frac{5}{18})$m/sec $=$ $(\frac{50}{9})$ m/sec Time taken to cover 400 meters = $(400\times \frac{9}{50})$sec = 72 sec = 1$\frac{1}{5}$ minutes

Speed = $\frac{Distance}{Time}$ = $\frac{180}{6}$ = 30 meters 30 $\times$ $\frac{18}{5}$ = 108 km/hr