Question

3. Abdul, while driving to school, computes the average speed for his trip to be 20 km h-!. 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? ​

Answer 1

Let us assume that Abdul is travelling x kilometer distance while going to school.

Distance = Speed x Time

1)When it's average speed is 20 km/hr

x=v

1

×t

1

=20×t

1

2)When it's average speed is 30 km/hr

x=v

2

×t

2

=30×t

2

V

average

=

totaltimetaken

totaldistancetravelled

V

average

=

v

1

x

+

v

2

x

x+x

=

20

x

+

30

x

2x

=24 km h

−1