Susan is attending a talk at her sons school. There are 8 rows of 10 chairs where 54 parents are sitting. Susan noticed that every parent is either sitting on their own or next to one other person. What is the largest possible number of adjacent empty chair in a single row? 3 4 5 7 8

Answer: 4

Step-by-step explanation:

To fit the maximum amount of people in one row, you would have 3 couples and 1 single = 7 parents.

If we continue the maximum amount of people for 7 rows, we get 49 parents seated.

Since a total of 54 parents are seated, that leaves 54 - 49 = 5 parents remaining to be seated in the last row. These parents can be seated as 2 couples and 1 single. If you put the single at the end of the row, there will be 4 seats between the couple and the single.

Couple, Couple, Open, Couple, Couple, Open, Open, Open, Open, Single