Question

A car moves with a speed of 40 km/h for 15 minutes and then with a speed of 60 km/h for the next 15 minutes. The total distance covered by the car is:
(i) 100 km (ii) 25 km (iii) 15 km (iv) 10 km
6.

Answer 1

First case:

         40 km/h = _?_ m/s

                        = 40 * 5/18 = 11.11 m/s (approx)

         15 min = _?_ sec

                     = 15 * 60 = 900 sec

         Distance = Speed * Time

                         = 11.11 * 900 = 10000 m

Second case:

         60 km/h = _?_ m/s

                        = 60 * 5/18 = 16.67 m/s (approx)

         15 min = 900 sec

         Distance = 16.67 * 900 = 15000 m

Total distance = 10000 + 15000 = 25000 m

       

                      1000 m = 1 km

⇒ Answer = 25 km