Question

A bus travels the first one-third distance at a speed of 10 km h-1, the next one-third distance at a speed of 20 km h-¹ and the next one-third distance at a speed of 30 km h-1. The average speed of the bus is:​

Answer 1

To find the average speed of the bus, you can use the formula:

Average Speed = Total Distance / Total Time

Let's assume the total distance traveled by the bus is D.

The time taken to cover the first one-third distance (D/3) at a speed of 10 km/h is (D/3) / 10 = D / 30 hours.

The time taken to cover the next one-third distance (D/3) at a speed of 20 km/h is also D / 30 hours.

The time taken to cover the final one-third distance (D/3) at a speed of 30 km/h is (D/3) / 30 = D / 90 hours.

The total time taken for the entire journey is:

Total Time = D / 30 + D / 30 + D / 90 = 5D / 90 = D / 18 hours.

Now, we can calculate the average speed:

Average Speed = Total Distance / Total Time = D / (D / 18) = 18 km/h.

So, the average speed of the bus is 18 km/h.