Question

On their most recent 8-mile training run, Pepe averaged a speed of

I of a mile in 4.5 minutes, while Paula averaged of a mile in 7.5

minutes.

How many minutes did it take the faster runner to finish the 8 mile

run?

Answer 1

36 minutes

Explanation:

Given that:

The length of run = 8 miles

Average speed of Pepe = 4.5 minutes per minute

Average speed of Paula = 7.5 minutes per minute

To find:

Minutes taken by the faster runner to finish the 8 mile run?

Solution:

First of all, let us have a look at the relation between Time and Speed.

`Speed = (Distance)/(Time)`

If the distance is a constant, then

`Speed \propto (1)/(Time)`

i.e. Speed is inversely proportional to time.

That means faster runner will take smaller amount of time.

So, faster runner is Pepe who is taking lesser time.

Time taken to complete 1 mile = 4.5 minutes

Time taken to complete 8 miles = 4.5
`*` 8 minutes = 36 minutes

So, the faster runner i.e. Pepe takes 36 minutes.