There was an equal number of tables and benches in the morning. At 4 p.m., some tables were added and some benches were removed, resulting in the number of tables being increased by 20% while the number of benches decreased by 40%. At 7 p.m. the number of tables increased by 50%. If a total of 68 tables were added during the day, how many more tables than benches were there in the end?

At 4 p.m.	Tables	Benches
Before	1 u	1 u
Change	+ 0.2 u	- 0.4 u
After	1.2 u	0.6 u

At 7 p.m.	Tables	Benches
Before	1.2 u	0.6 u
Change	+ 0.6 u	No change
After	1.8 u	0.6 u

Number of tables added
= 20% x 1 u
= ²⁰₁₀₀ x 1 u
= 0.2 u

Number of benches removed
= 40% x 1 u 
= ⁴⁰₁₀₀ x 1 u
= 0.4 u

Number of tables increased by tables at 7 p.m.
= 50% x 1.2 u
= ⁵⁰₁₀₀ x 1.2 u
= 0.6 u

Number of tables added during the day
= 1.8 u - 1 u
= 0.8 u

0.8 u = 68

1 u = 68 ÷ 0.8 = 85

Number of more tables than benches in the end
= 1.8 u - 0.6 u
= 1.2 u
= 1.2 x 85
= 102

Answer(s): 102