90% of Linda's amount was $468 more than Seth's amount. When Linda spent 55% of her amount and Seth spent 30% of his amount, they had the same amount of amount left. Find the amount that Seth had at first.

	90% of Linda's amount	Linda's amount	Seth's amount
Before	126 u	140 u	90 u
Change		- 77 u (- 55%)	- 27 u (- 30%)
After		63 u	63 u

Percentage of Linda's amount left
= 100% - 55%
= 45%

Percentage of Seth's amount left
= 100% - 30%
= 70%

45% = ⁴⁵₁₀₀ = ⁹₂₀
70% = ⁷⁰₁₀₀ = ⁷₁₀

The amounts of amount that Linda and Seth had left were the same.
Make the numerators the same.

⁹₂₀ of Linda's amount = ⁷₁₀ of Seth's amount
⁶³₁₄₀ of Linda's amount = ⁶³₉₀ of Seth's amount

Amount that Linda had = 140 u

90% of the amount that Linda had
= 140 u x 90%
= 140 u x ⁹⁰₁₀₀
= 126 u

Difference between 90% of Linda's amount and Seth's amount
= 126 u - 90 u 
= 36 u

36 u = 468
1 u = 468 ÷ 36 = 13

Amount that Seth had at first
= 90 u
= 90 x 13
= $1170

Answer(s): $1170