Prakhar goes from his home to school at a speed of 24 km/hr and returns at the speed of 36 km/hr. Find the average speed for the whole journey.

Correct option is B

Given:

Prakhar goes from his home to school at a speed of 24 km/hr and returns at the speed of 36 km/hr.

Formula Used:

The formula for average speed when the distance is the same for both journeys is:

Average Speed =  $$\frac{(2 × Speed_1 × Speed_2) }{ (Speed_1 + Speed_2)}$$​​

Solution:

Speed₁ = 24 km/hr.

Speed₂ = 36 km/hr.

Using the formula for average speed:

Average Speed = $$\frac{(2 × 24 × 36) }{ (24 + 36)}$$​​

Average Speed = $$\frac{1728 }{60}$$​​

Average Speed = 28.8 km/hr