Let's denote the number of adults as \( x \) and the number of children as \( y \).
We have the following information:
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The total number of attendees (adults + children) is 500: \[ x + y = 500 \]
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The total revenue from admissions needs to be $3,500, where adults are charged $10 and children are charged $5: \[ 10x + 5y = 3500 \]
Now we have a system of equations:
- \( x + y = 500 \) (Equation 1)
- \( 10x + 5y = 3500 \) (Equation 2)
We can simplify Equation 2 by dividing everything by 5: \[ 2x + y = 700 \quad (Equation 3) \]
Now we can solve this system using substitution or elimination. Let's substitute Equation 1 into Equation 3.
From Equation 1, we can express \( y \) in terms of \( x \): \[ y = 500 - x \]
Now we substitute this into Equation 3: \[ 2x + (500 - x) = 700 \] \[ 2x + 500 - x = 700 \] \[ x + 500 = 700 \] \[ x = 200 \]
Now, substitute \( x \) back into Equation 1 to find \( y \): \[ 200 + y = 500 \] \[ y = 500 - 200 \] \[ y = 300 \]
So, the solution is:
- Number of adults \( x = 200 \)
- Number of children \( y = 300 \)
Thus, the PTA needs 200 adults and 300 children to attend to reach their goal of $3,500.