Answer:
105
Step-by-step explanation:
Basically she wants to ride each of the 10 ride 3 times
So she will ride 30 times
Each ride = 4 tickets
So 30 rides = 120 tickets
She already has 15 tickets, so to find the amount of tickets Riley needs, we need to do 120-15, which is 105
Hope this helps your brother :)
Have a great day!
