Question

A car moves at a speed of 20km/h for 15 minutes and then at a speed of 60 km/h for next 15 minutes. Calculate the total distance covered by the car.

Answer 1

Case 1

Speed=20 km/ h

Time=15 min or 1/4hrs

Distance=speed × time =5km

Case 2

Speed =60 km/h

Time =1/4hrs

Distance = speed × time =15 km

Total distance = 20km

Answer 2

Distance covered fast-

Speed of the car for the first 15 minutes:

20 Km/hr.

Now, By this speed the car travels 20 Km in an hour. An hour has 60 minutes.

So, 20 km = 60 minutes

Dividing both sides by 4,

We get, 5 km = 15 minutes

So the car travels 5km here.

For the second 15 minutes-

The car travels 60km/ hr

So, 60 km = 60 minutes

Dividing both sides by 4,

We get 15 Km = 15 minutes

So the car travels 15 km in this case.

So the total distance travelled by the car is (15+5) km = 20 km