During his morning walk, Harsh walks for 70 min. at a speed of 6 km/h and takes 14 rounds at a park.  Sanjeev takes 20 rounds of the same park in 50 minutes.  What is the speed of Sanjeev in km/h?

12

In 70 min Harsh covers =  6 × \(\frac{70}{60}\) = 7 km

                   14 rounds = 7 km

                   20 rounds = \(\frac{7}{14}\) × 20 = 10 km

So, Sanjeev covers 10 km in 50 minutes

                    His speed = \(\frac{10}{50/60}\) = 12 km/h