Marion and Henry collect erasers and buttons. Henry has 80 less erasers than buttons. Henry has 2 times the number of erasers Marion has, and Marion has 40% more buttons than Henry. After Marion gives Henry all of her erasers and Henry gives Marion 75% of his buttons, Henry has 5 less buttons than erasers. Find the number of buttons Marion has at first.

Marion		Henry
Buttons	Erasers	Buttons	Erasers
2.8 u + 112	1 u	2 u + 80	2 u
+ 1.5 u + 60	- 1 u	- 1.5 u - 60	+ 1 u
4.3 u + 172	0	0.5 u + 20	3 u

100%+ 40% = 140% 

140% x 2 u
= ¹⁴⁰₁₀₀ x 2 u
= 2.8 u

140% x 80
= ¹⁴⁰₁₀₀ x 80
= 112 

75% x 2 u
= ⁷⁵₁₀₀ x 2 u
= 1.5 u  

75% x 80 
= ⁷⁵₁₀₀ x 80
= 60 

If another 5 buttons are given to Henry, he will have equal number of buttons and erasers in the end.
3 u = 0.5 u + 20 + 5
3 u - 0.5 u = 25
2.5 u = 25

1 u = 25 ÷ 2.5 = 10

Number of buttons that Marion has at first
= 2.8 u + 112
= 2.8 x 10 + 112
= 28 + 112
= 140
 
Answer(s): 140