Xandra and Nick collect erasers and coins. Nick has 60 more coins than erasers. Nick has 2 times the number of erasers Xandra has, and Xandra has 25% more coins than Nick. After Xandra gives Nick all of her erasers and Nick gives Xandra 75% of his coins, Nick has 10 more erasers than coins. Find the number of coins Xandra has at first.

Xandra		Nick
Coins	Erasers	Coins	Erasers
2.5 u + 75	1 u	2 u + 60	2 u
+ 1.5 u + 45	- 1 u	- 1.5 u - 45	+ 1 u
4 u + 120	0	0.5 u + 15	3 u

100% + 25% = 125% 

125% x 2 u
= ¹²⁵₁₀₀ x 2 u
= 2.5 u

125% x 60
= ¹²⁵₁₀₀ x 60
= 75 

75% x 2 u
= ⁷⁵₁₀₀ x 2 u
= 1.5 u  

75% x 60 
= ⁷⁵₁₀₀ x 60
= 45 

If another 10 coins are given to Nick, he will have equal number of coins and erasers in the end.
3 u = 0.5 u + 15 + 10
3 u - 0.5 u = 25
2.5 u = 25

1 u = 25 ÷ 2.5 = 10

Number of coins that Xandra has at first
= 2.5 u + 75
= 2.5 x 10 + 75
= 25 + 75
= 100
 
Answer(s): 100