Jen and Caden collect stickers and coins. Caden has 80 less stickers than coins. Caden has 3 times the number of stickers Jen has, and Jen has 20% more coins than Caden. After Jen gives Caden all of her stickers and Caden gives Jen 70% of his coins, Caden has 7 more stickers than coins. Find the number of coins Jen has at first.

Jen		Caden
Coins	Stickers	Coins	Stickers
3.6 u + 96	1 u	3 u + 80	3 u
+ 2.1 u + 56	- 1 u	- 2.1 u - 56	+ 1 u
5.7 u + 152	0	0.9 u + 24	4 u

100%+ 20% = 120% 

120% x 3 u
= ¹²⁰₁₀₀ x 3 u
= 3.6 u

120% x 80
= ¹²⁰₁₀₀ x 80
= 96 

70% x 3 u
= ⁷⁰₁₀₀ x 3 u
= 2.1 u  

70% x 80 
= ⁷⁰₁₀₀ x 80
= 56 

If another 7 coins are given to Caden, he will have equal number of coins and stickers in the end.
4 u = 0.9 u + 24 + 7
4 u - 0.9 u = 31
3.1 u = 31

1 u = 31 ÷ 3.1 = 10

Number of coins that Jen has at first
= 3.6 u + 96
= 3.6 x 10 + 96
= 36 + 96
= 132
 
Answer(s): 132