Explanation:
First figure out how much one paddle board is for 3 hours. To figure that out multiply 3 by 3.75.
3 x 3.75=11.25
So for 1 paddle board it cost 11.25 for 3 hours. Since they need 2 paddle boards multiply 11.25 by 2 for the total cost of 2 paddle boards.
11.25 x 2 = 22.5
They can pay for 3 hour and will have 2.50 left over.