Answer:
3 large doors
Explanation:
Given

Represent small door with S and large with L

From the question, we understand that;

So, we have that


Required
Determine the number of Large doors that can be cut from the board
To do this, we simply divide the size of the board by the size of the large cabinet
i.e.


Convert feet to inches



Get the integer part of the decimal

Hence:
3 large doors can be gotten from the board