Question

5. A car covers the first half of the distance between two places at a speed of 40 km/h and the second half at 60 km/h. What is the average speed of the car?


plz answer briefly....​

Answer 1

Answer:

Average speed is total distance travelled divided by total time taken.

Let the distance travelled is 2x or half of distance is x.

The first half of distance x is travelled with speed of 40km/hr , so time taken is x/40hr.

Similarly time taken to travel remaining x km is at speed of 60km/hr, so time taken for this 2nd half of distance is x/60.

Now, total time taken to travel 2x distance is x/40+x/60 hr or 3x/120+2x/120hr or 5x/120 hr or x/24 hr.

The average speed of car is 2x/x/24 or 2*24 km/hr or 48km/hr.