Here ya go heres those last questions : )

The 3 bubble is the correct answer.

being that you're looking for 3.60 in quarters(25) and nickles (5) which add up to be 3.60 so 25q+5n=360

For 1 I would set it up like this:
360 = 5q + 5n

For 2 I would put cost per mile because it's multiplied by the number of miles.

For 3 I would say the customers purchased 5 kid tickets and 4 adult tickets 

For 4 I would do this:
P = each can of paint
and 
B = each bush

25P + 12.75B = 327

For 5 I would say that 2 represents the amount of waffle cones and 3 represents the amount of milkshakes.

As always, I hope this helps!