Roshel and Paul collect stickers and cards. Paul has 45 less stickers than cards. Paul has 4 times the number of stickers Roshel has, and Roshel has 40% more cards than Paul. After Roshel gives Paul all of her stickers and Paul gives Roshel 60% of his cards, Paul has 50 less cards than stickers. Find the number of cards Roshel has at first.

Roshel		Paul
Cards	Stickers	Cards	Stickers
5.6 u + 63	1 u	4 u + 45	4 u
+ 2.4 u + 27	- 1 u	- 2.4 u - 27	+ 1 u
8 u + 90	0	1.6 u + 18	5 u

100%+ 40% = 140% 

140% x 4 u
= ¹⁴⁰₁₀₀ x 4 u
= 5.6 u

140% x 45
= ¹⁴⁰₁₀₀ x 45
= 63 

60% x 4 u
= ⁶⁰₁₀₀ x 4 u
= 2.4 u  

60% x 45 
= ⁶⁰₁₀₀ x 45
= 27 

If another 50 cards are given to Paul, he will have equal number of cards and stickers in the end.
5 u = 1.6 u + 18 + 50
5 u - 1.6 u = 68
3.4 u = 68

1 u = 68 ÷ 3.4 = 20

Number of cards that Roshel has at first
= 5.6 u + 63
= 5.6 x 20 + 63
= 112 + 63
= 175
 
Answer(s): 175