Abdul, while driving to school, computes the average speed for his trip to be 20 km h^-1. On his return trip along the same route, there is less traffic and the average speed is 30 km h^-1. What is the average speed for Abdul’s trip?

Question

Philoid · Accepted Answer

Let, the school is at a distance of x km

Suppose the time taken while driving to school is t₁

Given,

Average speed = 20 km/h

Speed =

20 =

Time taken, t₁ = (1)

on returning from the trip the average speed is 30 km/h

Let, the time taken for the return trip is t₂

Speed =

30 =

So, Time taken, t₂ = (2)

Now, total distance of the whole trip from going to trip to returning back to school is:

Total distance = x + x

= 2x Km (3)

Time taken = +

=

= (4)

Now, we will calculate the average speed of the whole trip:

Average speed =

=

= 24 km/h

Therefore, the average speed for Abdul’s whole trip from going from to school to return back is 24 Km/h.

Abdul, while driving to school, computes the average speed for his trip to be 20 km h-1. On his return trip along the same route, there is less traffic and the average speed is 30 km h-1. What is the average speed for Abdul’s trip?