The Willis Middle School PTA is planning a carnival to raise money for the school's art department. They estimate that the event will be very popular and that they will have 400 people attend. They plan to charge adults $8 and children $3 for admission. The PTA wants to earn $2,500 from admission charges. How many adults and how many children need to attend for the PTA to reach their goal of $2500

1 answer

To solve this problem, we can use a system of equations based on the information given. Let:

  • \( x \) be the number of adults attending the carnival.
  • \( y \) be the number of children attending the carnival.

From the problem, we can set up the following equations:

  1. The total number of people attending is 400: \[ x + y = 400 \]

  2. The total revenue from admissions must be $2,500. The admission charges are $8 for adults and $3 for children: \[ 8x + 3y = 2500 \]

Now we can solve this system of equations. We can express \( y \) in terms of \( x \) using the first equation:

\[ y = 400 - x \]

Now, we can substitute this expression for \( y \) into the second equation:

\[ 8x + 3(400 - x) = 2500 \]

Expanding this gives:

\[ 8x + 1200 - 3x = 2500 \]

Combining like terms:

\[ 5x + 1200 = 2500 \]

Now, isolate \( x \):

\[ 5x = 2500 - 1200 \] \[ 5x = 1300 \] \[ x = \frac{1300}{5} = 260 \]

Now that we have \( x \), we can find \( y \):

\[ y = 400 - x = 400 - 260 = 140 \]

Thus, the number of adults that need to attend is 260 and the number of children that need to attend is 140.

To verify, we can check the revenue:

  • Revenue from adults: \( 260 \times 8 = 2080 \)
  • Revenue from children: \( 140 \times 3 = 420 \)
  • Total revenue: \( 2080 + 420 = 2500 \)

The calculations are correct, so the answer is:

  • 260 adults
  • 140 children