Answer: 5 bags
Step-by-step explanation:
Given : Mr. Daniel has acres of land in which he plans to fertilize.
Here
Each bag of fertilizer covers of an acre .
By using UNITARY METHOD ,the number of bags of fertilizer required for of an acre :-
If he bought 20 bags of fertilizer , then he left over = 20 -15 = 5 bags
hence, he left over with 5 bags of fertilizer.