There's two ways, you can either multiply 11 and 7 to get 77 and then divide by 2, OR, you can divide 11 by 2 and get 5.5 and multiply that by 7, hope this makes sense, if you don't understand just comment and I'll explain it more :)
Answer:
30 dollars
Step-by-step explanation:
4(5) + 10 = 20 + 10 = 30
If he starts out with $25 and to enter is $5 then he will be left with $20. 0.80 per ride then he can ride 25 times by diving 20 by 0.80