how miles did you drive

Question

a car rental company charges a daily rate of $37 plus $0.20 per mile for a certain car. Suppose that you rent that car for a day and your bill (before taxes) is $115. how many miles did you drive.

Answer 1

Hi, Ashley,

 

So, we know that the rental company charges $37/day, plus $.20 per mile. If we rented the car for one day, we can set up an equation as follows:

 

    Total cost for one day = $37 + $0.20 x (# of miles)

 

We know that we only rented for one day, and the total cost was $115, so we can modify the equation to say:

 

    $115 = $37 + $0.20 x (x)

 

Getting rid of the $ signs for clarity:

 

    115 = 37 + .2 (x)

 

Now let's solve for x. First, we will subtract 37 from both sides of the equation:

 

    115 = 37 + .2 (x)

    -37         -37

 

    78 = .2 (x)

 

Now we will divide by .2 on each side to get "x" all by itself:

 

    78 = .2 (x)

    .2        .2

 

   390 = x

 

So, to incur the given cost of $115 in one day, you must have driven 390 miles.