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

Answer:

Option 2: 14.06 minutes

Step-by-step 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

$Speed = \frac{distance}{time}$

$7.5 = \frac{distance}{0.25}$

$7.5 * 0.25 = Distance$

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,

$speed = \frac{distance}{time}$

$8 = \frac{1.875}{time}$

$time = \frac{1.875}{8}$

$time = 0.234375 hours$

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..