Final answer:
If the student does not play any games, they could get on 15 rides as per the equation 2.50x + y = 15.
Step-by-step explanation:
In the equation 2.50x + y = 15, if the student does not play any games (x = 0), we can determine the number of rides (y) they could get on. To find y, simply substitute x with 0 and solve the equation:
y = 15 - 2.50(0)
y = 15
Therefore, if the student does not play any games, they could get on 15 rides.