30% of Cody's savings was $36 more than 40% of George's savings. After Cody spent ³₁₀ of his savings and George spent 40% of his savings, Cody had $99 more than George. How much was Cody's saving at first?

	George	Cody
Before	15 u	20 u + 120
Change	- 6 u	- 6 u - 36
After	9 u	14 u + 84
Comparing George and Cody in the end		99 more

30% = ³⁰₁₀₀ = ³₁₀

40% = ⁴⁰₁₀₀ = ²₅

³₁₀ Cody = ²₅ George + 36 

Make the numerators the same. LCM of 3 and 2 is 6.
 
3x210x2 Cody = 2x35x3 George + 36 
620 Cody = 615 George + 36 

Simplify the fractions.
¹₂₀ Cody = ¹₁₅ George + 6

Let ¹₁₅ George be 1 u.

George's savings at first = 15 u

¹₂₀ Cody = ¹₁₅ George + 6
Let ¹₂₀ Cody be 1 u + 6.

Cody's savings at first
= 20 x (1 u + 6) 
= 20 u + 120

Savings that George spent
= 40% x 15 u
= ⁴⁰₁₀₀ x 15 u
= 6 u

Savings that Cody spent 
= ³₁₀ x (20 u + 120)
= 6 u + 36 

Cody had $99 more than George in the end. If another $99 was given to George, the amount that each had in the end would be the same.

14 u + 84 = 9 u + 99 
14 u - 9 u = 99 - 84
5 u = 15

1 u = 15 ÷ 5 = 3

Savings that Cody had at first
= 20 u + 120
= 20 x 3 + 120
= 60 + 120
= $180

Answer(s): $180