Explanation:
t is the number of ride tickets she can buy.
=>
![15 + t * 0.5 \leqslant 24](https://img.qammunity.org/2022/formulas/mathematics/high-school/iq4wlh3xmpa5n1xuzrp2trdbymtn0p137d.png)
she has to pay $15 just for entering. the rest of the money she can use for ride tickets.
so, whatever she does, she has to stay inside the $24 limit, as she does not have more money.
the $15 admission goes off the $24 available money. that leaves $9.
each ride ticket costs $0.50, so she can buy max. 9/0.5 = 18 tickets. she can buy fewer tickets, but she cannot buy more than these 18 tickets.
so, again
![15 + t * 0.5 \leqslant 24](https://img.qammunity.org/2022/formulas/mathematics/high-school/iq4wlh3xmpa5n1xuzrp2trdbymtn0p137d.png)
![t * 0.5 \leqslant 24 - 15 = 9](https://img.qammunity.org/2022/formulas/mathematics/high-school/oa8jcuk4ln3ichpbak25vn8ss4v56dcqft.png)
![t * 0.5 \leqslant 9](https://img.qammunity.org/2022/formulas/mathematics/high-school/557cxfoahmdz2hdgf5s6nyc0hzni8y83kv.png)
![t \leqslant 9 / 0.5 = 9 / (1 / 2) = 2 * 9 / 1 \\ = 18](https://img.qammunity.org/2022/formulas/mathematics/high-school/wbwxkghqmyp9js072ramg64vkpu15veune.png)
![t \leqslant 18](https://img.qammunity.org/2022/formulas/mathematics/high-school/gy6taz6tolqzamykeclph1zl6tlpr4hklp.png)