Question

Monica runs on a treadmill at an average speed of 7.5 miles per hour for 15 minutes. If, the next day, she runs the same distance at a speed of 8 miles per hour, what is the average time taken?

Answer 1

Option 2: 14.06 minutes

Explanation:

For the first scenario, we will convert the minutes into hours first to get all the quantities in same unit

So,

15 minutes = 1/4 hours = 0.25 hours

Speed = 7.5 miles per hour

Now using the speed, distance and time formula

Speed = distance/time

`Speed = (distance)/(time)`

`7.5 = (distance)/(0.25)`

`7.5 * 0.25 = Distance`

Distance = 1.875 miles

So the distance for 1st day is 1.875 miles.

For next day

Speed = 8 miles per hour

Distance = 1.875

So,

`speed = (distance)/(time)`

`8 = (1.875)/(time)`

`time = (1.875)/(8)`

`time = 0.234375 hours`

Converting the hours into minutes will give

0.234375 * 60 min = 14.0625 minutes

Rounding off to two decimals = 14.06 min

So 2nd option is correct..