There are 28 tables for customers at Mesa Grill Restaurant. The tables are either two-seat tables or four-seat tables. When all the tables are full, there will be 90 customers in the restaurant. How many two-seat tables are at the restaurant?

Explanation

To solve this problem, set up two equations based on the information given:Let x be the number of two-seat tables and y be the number of four-seat tables. Then, x + y = 28, because there are 28 tables in total.The total number of seats is given as 90, so you have another equation: 2x + 4y = 90.Solving these equations simultaneously, substitute y = 28 - x into the second equation:2x + 4(28 - x) = 902x + 112 - 4x = 90-2x + 112 = 90-2x = 90 - 112-2x = -22x = 11So, there are 11 two-seat tables. The other options provide incorrect results because they do not satisfy both conditions of the problem.