25% of Fabian's savings was $36 more than 30% of Seth's savings. After Fabian spent ¹₃ of his savings and Seth spent 40% of his savings, Seth had $104 less than Fabian. How much was Seth's saving at first?

	Seth	Fabian
Before	10 u	12 u + 144
Change	- 4 u	- 4 u - 48
After	6 u	8 u + 96
Comparing Seth and Fabian in the end		104 more

25% = ²⁵₁₀₀ = ¹₄

30% = ³⁰₁₀₀ = ³₁₀

¹₄ Fabian = ³₁₀ Seth + 36 

Make the numerators the same. LCM of 1 and 3 is 3.
 
1x34x3 Fabian = 3x110x1 Seth + 36 
312 Fabian = 310 Seth + 36 

Simplify the fractions.
¹₁₂ Fabian = ¹₁₀ Seth + 12

Let ¹₁₀ Seth be 1 u.

Seth's savings at first = 10 u

¹₁₂ Fabian = ¹₁₀ Seth + 12
Let ¹₁₂ Fabian be 1 u + 12.

Fabian's savings at first
= 12 x (1 u + 12) 
= 12 u + 144

Savings that Seth spent
= 40% x 10 u
= ⁴⁰₁₀₀ x 10 u
= 4 u

Savings that Fabian spent 
= ¹₃ x (12 u + 144)
= 4 u + 48 

Seth had $104 less than Fabian in the end. If another $104 was given to Seth, the amount that each had in the end would be the same.

8 u + 96 = 6 u + 104 
8 u - 6 u = 104 - 96
2 u = 8

1 u = 8 ÷ 2 = 4

Savings that Seth had at first
= 10 u 
= 10 x 4
= $40

Answer(s): $40