Question

It will take Adam four hours to drive to Disney Park, and 2.5 times less time if driving 45 mph faster. What is the distance Adam should cover to get to the park?

Answer 1

Hello!

The answer is:

The distance to over by Adam to get to the park is 108 miles.

Why?

To solve the problem, we need to write two equations using he given information about the times and his speed.

So,

For the first equation we have: Travel to Disney Park

$time=4hours$

$Distance=v*4hours$

For the second equation we have: Travel back from Disnery Park

$time=4hours-2.5hours=1.5hours$

$Speed=v+45mph$

$Distance=(v+45mph)*1.5hours$

Then, if Adam covered the same distance going and coming back, we have:

$v*4hours=(v+45mph)*1.5hours$

$v*4hours=v*1.5hours+45mph*1.5hours$

$v*4hours-v*1.5hours=45mph*1.5hours$

$v*2.5hours=67.5miles$

$v=\frac{67.5miles}{2.5hours}=27\frac{miles}{hour}=27mph$

We have that the speed when he was going to Disney Park was 27 mph.

Now, to calculate the distance, we need to substitute the obtained speed in any of the two first equations.

Therefore, substituting the speed into the second equation, we have:

$Distance=(v+45mph)*1.5hours$

$Distance=(27mph+45mph)*1.5hours=72mph*1.5hours=108miles$

Hence, we have that the distance that Adam should cover to get to the park is 108 miles.

Havea nice day!