At a zoo, youth tickets cost [tex]\$5[/tex] and adult tickets cost [tex]\$9[/tex]. A group that purchased [tex]x[/tex] youth tickets and [tex]y[/tex] adult tickets spent [tex]\$90[/tex] on tickets. What is the domain of the relationship?

A. [tex]x \leq 5[/tex]

B. [tex]0 \leq x \leq 5[/tex]

C. [tex]0 \leq x \leq 18[/tex]

D. [tex]x \leq 18[/tex]



Answer :

To find the domain of the relationship, we need to determine the range of possible values that [tex]\( x \)[/tex] (the number of youth tickets) can take, given the total amount spent on tickets is \[tex]$90 and the costs of the youth and adult tickets are \$[/tex]5 and \[tex]$9, respectively. 1. Formulating the equation: We are given: - Youth ticket cost: \$[/tex]5
- Adult ticket cost: \[tex]$9 - Total amount spent: \$[/tex]90

We can set up the following equation based on the information provided:
[tex]\[ 5x + 9y = 90 \][/tex]

2. Solving for [tex]\( x \)[/tex]:
To find the domain of [tex]\( x \)[/tex], let's consider the extreme cases:

- Maximum value of [tex]\( x \)[/tex]: This happens when the number of adult tickets [tex]\( y \)[/tex] is minimized. The minimum value for [tex]\( y \)[/tex] is 0. If [tex]\( y = 0 \)[/tex], the equation simplifies to:
[tex]\[ 5x = 90 \Rightarrow x = \frac{90}{5} = 18 \][/tex]

So, the maximum possible value for [tex]\( x \)[/tex] is 18.

3. Minimum value of [tex]\( x \)[/tex]: [tex]\( x \)[/tex] can be a minimum of 0 since the number of tickets cannot be negative. Now the equation would be:
[tex]\[ 5(0) + 9y = 90 \Rightarrow y = \frac{90}{9} = 10 \][/tex]

Therefore, the minimum value for [tex]\( x \)[/tex] is 0.

4. Combining these constraints:
[tex]\( x \)[/tex] can range from 0 to 18, inclusive.

Therefore, the domain of the relationship [tex]\( x \)[/tex] is:
[tex]\[ 0 \leq x \leq 18 \][/tex]

Given the multiple-choice options, the correct answer is:
[tex]\[ \boxed{0 \leq x \leq 18} \][/tex]