Question

A man travels 200 km distance at 40 km/hr and the next 400 km at 80 km/hr. Find the average speed of the man.

1. 50 km/hr
2. 60 km/hr
3. 65 km/hr
4. 70 km/hr

Answer 1

Correct Answer - Option 2 : 60 km/hr

Given:

A man travels 200 km distance at 40 km/hr

and next 400 km distance at 80 km/hr

Formula Used:

Distance = Speed × Time

Average speed = (Total distance)/(Total time)

Calculation:

Let t1 hour be the time taken to cover 200 km distance 

And Let t2 hour be the time taken to cover 400 km distance 

t₁ = 200/40

⇒ t₁ = 5 hours

t₂ = 400/80

⇒ t₂ = 5 hours

Average speed = (200 + 400)/(5 + 5)

⇒ Average speed = 600/10

⇒ 60 km/hr

∴ The average speed of a man travel by the whole journey is 60 km/hr.