Answer:
10 Hamburgers.
Explanation:
First, I will eliminate the delivery fee:
25 - 5 = 20
We're left with 20$ that we KNOW is solely for the burgers..
Each burger costs 2$..
I will divide the price spent on burgers by the price of a burger to get the number of burgers he ordered..
20 / 2 = 10
Answer: He ordered 10 hamburgers.