80% of Sarah's amount was $2856 more than Warren's amount. When Sarah spent 65% of her amount and Warren spent 35% of his amount, they had the same amount of amount left. Find the amount that Warren had at first.

	80% of Sarah's amount	Sarah's amount	Warren's amount
Before	208 u	260 u	140 u
Change		- 169 u (- 65%)	- 49 u (- 35%)
After		91 u	91 u

Percentage of Sarah's amount left
= 100% - 65%
= 35%

Percentage of Warren's amount left
= 100% - 35%
= 65%

35% = ³⁵₁₀₀ = ⁷₂₀
65% = ⁶⁵₁₀₀ = ¹³₂₀

The amounts of amount that Sarah and Warren had left were the same.
Make the numerators the same.

⁷₂₀ of Sarah's amount = ¹³₂₀ of Warren's amount
⁹¹₂₆₀ of Sarah's amount = ⁹¹₁₄₀ of Warren's amount

Amount that Sarah had = 260 u

80% of the amount that Sarah had
= 260 u x 80%
= 260 u x ⁸⁰₁₀₀
= 208 u

Difference between 80% of Sarah's amount and Warren's amount
= 208 u - 140 u 
= 68 u

68 u = 2856
1 u = 2856 ÷ 68 = 42

Amount that Warren had at first
= 140 u
= 140 x 42
= $5880

Answer(s): $5880