Juan measured the location for the bookcase and realized that his shelves can be no more than 13 4 feet wide.

a. What is the maximum number of shelves Juan could build for this new bookcase using the lumber he bought?
b. How many DVD cases will he be able to store on each of the shorter shelves?
c. How many paperback books will he be able to store on each of the shorter shelves?

It would help if you proofread your questions before you posted them.

"13 4 feet wide" = 134, 13.4, 13feet 4 inches?

Also lacking data.

How much lumber did he buy?
How big are DVD cases and paperback books?