Question

Question #6b408

Answer 1

Time taken =86.035 minutes

Explanation:

This question is based on different units .
The distance to be covered is given by kilometers.
The speed of the runner is given in miles per hour.
And the time taken is asked to be calculated in minutes.

Now we should take a single unit system .Since the time taken is

asked in minutes we take the unit of time as minutes . And there

are two different units are given for length (distance). As we should

consider only one unit for a quantity , we take miles as our unit

for length .

     1 kilometer=0.621371 miles.
     15 kilometers=15 x  0.621371  miles  =9.320565 miles.

Hence total distance to be covered is 9.320565 miles .

`S=v*t`

where

S is the distance covered,
v is the speed,
and t is the time taken .

`t=S/v`= `9.320565/6.5` `Hours`
`t=1.434` `Hours`

The time taken is given in hour we should convert it into minutes.

`1Hour=60 mins`
`1.434Hours=1.434xx60 mins`=86.035`mins`

Hence the total time taken to cover 15 kilometers with the speed

6.5 miles per hour is 86.035 minutes