Risa and Jeremy collect pens and coins. Jeremy has 64 more coins than pens. Jeremy has 5 times the number of pens Risa has, and Risa has 25% more coins than Jeremy. After Risa gives Jeremy all of her pens and Jeremy gives Risa 75% of his coins, Jeremy has 60 more pens than coins. Find the number of coins Risa has at first.

Risa		Jeremy
Coins	Pens	Coins	Pens
6.25 u + 80	1 u	5 u + 64	5 u
+ 3.75 u + 48	- 1 u	- 3.75 u - 48	+ 1 u
10 u + 128	0	1.25 u + 16	6 u

100% + 25% = 125% 

125% x 5 u
= ¹²⁵₁₀₀ x 5 u
= 6.25 u

125% x 64
= ¹²⁵₁₀₀ x 64
= 80 

75% x 5 u
= ⁷⁵₁₀₀ x 5 u
= 3.75 u  

75% x 64 
= ⁷⁵₁₀₀ x 64
= 48 

If another 60 coins are given to Jeremy, he will have equal number of coins and pens in the end.
6 u = 1.25 u + 16 + 60
6 u - 1.25 u = 76
4.75 u = 76

1 u = 76 ÷ 4.75 = 16

Number of coins that Risa has at first
= 6.25 u + 80
= 6.25 x 16 + 80
= 100 + 80
= 180
 
Answer(s): 180