Answer :

To determine how much money Ron finished with, follow these steps:

1. Calculate the total amount spent:

  - Amount spent on rides: $15

  - Amount spent on lunch: $8.65

  - Amount spent on a gift: $5

  Total amount spent:

[tex]\[ 15 + 8.65 + 5 = 28.65 \][/tex]

2. Calculate the remaining amount after spending:

 

- Initial amount: $50

  - Total amount spent: $28.65

  Remaining amount:

[tex]\[ 50 - 28.65 = 21.35 \][/tex]

3. Add the cash prize won:

 

- Cash prize: $10

  Total money after winning the prize:

 

[tex]\[ 21.35 + 10 = 31.35 \][/tex]

Therefore, Ron finished with $31.35.