Let the cost of an adult ticket be \( x \). Then, the cost of a child ticket would be \( x - 3 \).
The equation for the total cost of the tickets can be expressed as: \[ 3x + 3(x - 3) = 75 \]
Now, simplifying this equation: \[ 3x + 3x - 9 = 75 \] \[ 6x - 9 = 75 \] \[ 6x = 75 + 9 \] \[ 6x = 84 \] \[ x = 14 \]
So, the cost of an adult ticket (\( x \)) is \( 14 \) dollars.
The cost of a child ticket is: \[ x - 3 = 14 - 3 = 11 \text{ dollars} \]
Thus, the prices are:
- Adult ticket: $14
- Child ticket: $11
So the correct response is: an adult ticket is $14 and a child ticket is $11.