I think you would divide 72 by 3 to get 24i think you would divide 72 by 3 to get 24 then subtract 4 from 24 to get 20. Therefore 1 book cost $20 and the other cost $52. I may be wrong though.
11 hours and 15 minutes because doing 2.25, which is equal to 2 hours and 15 minutes, times 5 you end up getting 11.25, and converting that to time you get 11 hours and 15 minutes.
