At the office building, Floor X and Floor Y had an equal number of tables at first. If 7 tables were removed from Floor Y and 4 times as many tables were removed from Floor X as Floor Y, the number of tables in Floor Y would be 4 times as many as in Floor X. Find the number of tables on each floor.

	Floor X	Floor Y
Before	1 u	1 u
Change	- 28	- 7
After	1 u - 28	1 u - 7

Number of tables removed from Floor X
= 4 x 7
= 28

Number of tables on Floor X and Floor Y at first is the same.

Number of tables on Floor Y is 4 times as many as Floor X in the end. If the number of tables on Floor X increases by 4 times, the number of tables on Floor X and Floor Y will be the same.

4(1 u - 28) = 1 u - 7
4 u - 112 = 1 u - 7 
4 u - 1 u = 112 - 7
3 u = 105

1 u = 105 ÷ 3 = 35

Number of tables in each floor
= 1 u
= 35

Answer(s): 35