Penelope and Jenson collect marbles and cards. Jenson has 40 less marbles than cards. Jenson has 4 times the number of marbles Penelope has, and Penelope has 40% more cards than Jenson. After Penelope gives Jenson all of her marbles and Jenson gives Penelope 75% of his cards, Jenson has 50 more marbles than cards. Find the number of cards Penelope has at first.

Penelope		Jenson
Cards	Marbles	Cards	Marbles
5.6 u + 56	1 u	4 u + 40	4 u
+ 3 u + 30	- 1 u	- 3 u - 30	+ 1 u
8.6 u + 86	0	1 u + 10	5 u

100%+ 40% = 140% 

140% x 4 u
= ¹⁴⁰₁₀₀ x 4 u
= 5.6 u

140% x 40
= ¹⁴⁰₁₀₀ x 40
= 56 

75% x 4 u
= ⁷⁵₁₀₀ x 4 u
= 3 u  

75% x 40 
= ⁷⁵₁₀₀ x 40
= 30 

If another 50 cards are given to Jenson, he will have equal number of cards and marbles in the end.
5 u = 1 u + 10 + 50
5 u - 1 u = 60
4 u = 60

1 u = 60 ÷ 4 = 15

Number of cards that Penelope has at first
= 5.6 u + 56
= 5.6 x 15 + 56
= 84 + 56
= 140
 
Answer(s): 140