Jean and David collect pencils and coins. David has 65 less pencils than coins. David has 4 times the number of pencils Jean has, and Jean has 40% more coins than David. After Jean gives David all of her pencils and David gives Jean 60% of his coins, David has 8 more pencils than coins. Find the number of coins Jean has at first.

Jean		David
Coins	Pencils	Coins	Pencils
5.6 u + 91	1 u	4 u + 65	4 u
+ 2.4 u + 39	- 1 u	- 2.4 u - 39	+ 1 u
8 u + 130	0	1.6 u + 26	5 u

100%+ 40% = 140% 

140% x 4 u
= ¹⁴⁰₁₀₀ x 4 u
= 5.6 u

140% x 65
= ¹⁴⁰₁₀₀ x 65
= 91 

60% x 4 u
= ⁶⁰₁₀₀ x 4 u
= 2.4 u  

60% x 65 
= ⁶⁰₁₀₀ x 65
= 39 

If another 8 coins are given to David, he will have equal number of coins and pencils in the end.
5 u = 1.6 u + 26 + 8
5 u - 1.6 u = 34
3.4 u = 34

1 u = 34 ÷ 3.4 = 10

Number of coins that Jean has at first
= 5.6 u + 91
= 5.6 x 10 + 91
= 56 + 91
= 147
 
Answer(s): 147