Darell parks his car in a parking garage. The garage charges a certain amount for the first hour and an hourly rate for each additional hour. The total charge for 3 hours is $10.65. The total charge for 6 hours is $15.30.

Complete the equation that describes the relationship between the total charge, C, and the length of time in hours, h.
Write your answer using whole numbers or decimals rounded to the nearest hundredth.
C=
h+

1 answer

To establish the relationship between the total charge \( C \) and the length of time in hours \( h \), we can define the equation based on the information provided.

Let:

  • \( x \) be the charge for the first hour,
  • \( y \) be the charge for each additional hour.

From the information given, we can set up the following equations based on the total charges for 3 hours and 6 hours:

  1. For 3 hours: \[ C = x + 2y = 10.65 \quad \text{(Equation 1)} \]

  2. For 6 hours: \[ C = x + 5y = 15.30 \quad \text{(Equation 2)} \]

Now we can solve these two equations to find the values of \( x \) and \( y \).

Subtract Equation 1 from Equation 2 to eliminate \( x \):

\[ (x + 5y) - (x + 2y) = 15.30 - 10.65 \] \[ 3y = 4.65 \]

Solving for \( y \): \[ y = \frac{4.65}{3} = 1.55 \]

Now substitute \( y = 1.55 \) back into Equation 1 to solve for \( x \):

\[ x + 2(1.55) = 10.65 \] \[ x + 3.10 = 10.65 \] \[ x = 10.65 - 3.10 = 7.55 \]

Now we have \( x = 7.55 \) and \( y = 1.55 \).

We can write the relationship as:

  • \( C = x + (h - 1)y \) for \( h \geq 1 \)

Thus, substituting the values for \( x \) and \( y \):

\[ C = 7.55 + (h - 1)(1.55) \]

Which can be rewritten to show it clearly as: \[ C = 7.55 + 1.55h - 1.55 \] \[ C = 1.55h + 6.00 \]

So, the complete equation that describes the relationship is:

\[ C = 1.55h + 6.00 \]

In this format:

  • The equation is \( C = 1.55h + 6.00 \)
  • Where \( C \) is in dollars and \( h \) is the number of hours parked.