A restaurant has 10 booths that will seat up to 4 people each

A restaurant has 10 booths that will seat up to 4 people each. If 20 people are seated in booths, and NO booths are empty, what is the greatest possible number of booths that could be filled with 4 people?

1. 0
2. 1
3. 2
4. 3
5. 5

Answer

The correct answer is D.

Because no booths can be empty, assume 1 person sitting in each booth. That leaves 10 people remaining.

How many booths can be filled up with another 3 people each? You can get 3 groups of 3 people from the 10 remaining people. That means that you can fill at most 3 booths with 4 people.