80% of Kimberly's amount was $680 more than Oliver's amount. When Kimberly spent 65% of her amount and Oliver spent 35% of his amount, they had the same amount of amount left. Find the amount that Oliver had at first.

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

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

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

35% = ³⁵₁₀₀ = ⁷₂₀
65% = ⁶⁵₁₀₀ = ¹³₂₀

The amounts of amount that Kimberly and Oliver had left were the same.
Make the numerators the same.

⁷₂₀ of Kimberly's amount = ¹³₂₀ of Oliver's amount
⁹¹₂₆₀ of Kimberly's amount = ⁹¹₁₄₀ of Oliver's amount

Amount that Kimberly had = 260 u

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

Difference between 80% of Kimberly's amount and Oliver's amount
= 208 u - 140 u 
= 68 u

68 u = 680
1 u = 680 ÷ 68 = 10

Amount that Oliver had at first
= 140 u
= 140 x 10
= $1400

Answer(s): $1400