Abi and Fabian collect coins and pencils. Fabian has 80 less coins than pencils. Fabian has 2 times the number of coins Abi has, and Abi has 30% more pencils than Fabian. After Abi gives Fabian all of her coins and Fabian gives Abi 70% of his pencils, Fabian has 12 less pencils than coins. Find the number of pencils Abi has at first.

Abi		Fabian
Pencils	Coins	Pencils	Coins
2.6 u + 104	1 u	2 u + 80	2 u
+ 1.4 u + 56	- 1 u	- 1.4 u - 56	+ 1 u
4 u + 160	0	0.6 u + 24	3 u

100%+ 30% = 130% 

130% x 2 u
= ¹³⁰₁₀₀ x 2 u
= 2.6 u

130% x 80
= ¹³⁰₁₀₀ x 80
= 104 

70% x 2 u
= ⁷⁰₁₀₀ x 2 u
= 1.4 u  

70% x 80 
= ⁷⁰₁₀₀ x 80
= 56 

If another 12 pencils are given to Fabian, he will have equal number of pencils and coins in the end.
3 u = 0.6 u + 24 + 12
3 u - 0.6 u = 36
2.4 u = 36

1 u = 36 ÷ 2.4 = 15

Number of pencils that Abi has at first
= 2.6 u + 104
= 2.6 x 15 + 104
= 39 + 104
= 143
 
Answer(s): 143