Answer:
A: 75 - 30 - (12.50*Y) find the amount of Y
B: You take 75 (which is your total cash) then you take the $30 that you were going to buy with food out of it. Then, you take $12.50, which is the cost of the ticket, and multiply it by a number Y. The answer is what the Y is.
C: To figure this out, you must take 75 - 30 - 12.50*5. The amount you would pay for the tickets would be $62.50, so the answer to question c is no.
I hope this helped! :)