Tiffany and Tom collect coins and erasers. Tom has 50 less coins than erasers. Tom has 2 times the number of coins Tiffany has, and Tiffany has 40% more erasers than Tom. After Tiffany gives Tom all of her coins and Tom gives Tiffany 60% of his erasers, Tom has 24 less erasers than coins. Find the number of erasers Tiffany has at first.

Tiffany		Tom
Erasers	Coins	Erasers	Coins
2.8 u + 70	1 u	2 u + 50	2 u
+ 1.2 u + 30	- 1 u	- 1.2 u - 30	+ 1 u
4 u + 100	0	0.8 u + 20	3 u

100%+ 40% = 140% 

140% x 2 u
= ¹⁴⁰₁₀₀ x 2 u
= 2.8 u

140% x 50
= ¹⁴⁰₁₀₀ x 50
= 70 

60% x 2 u
= ⁶⁰₁₀₀ x 2 u
= 1.2 u  

60% x 50 
= ⁶⁰₁₀₀ x 50
= 30 

If another 24 erasers are given to Tom, he will have equal number of erasers and coins in the end.
3 u = 0.8 u + 20 + 24
3 u - 0.8 u = 44
2.2 u = 44

1 u = 44 ÷ 2.2 = 20

Number of erasers that Tiffany has at first
= 2.8 u + 70
= 2.8 x 20 + 70
= 56 + 70
= 126
 
Answer(s): 126