50% of Risa's amount was $2800 less than Tim's amount. When Risa spent 35% of her amount and Tim spent 70% of his amount, they had the same amount of amount left. Find the amount that Tim had at first.

	Risa	Tim
Before	60 u	130 u
Change	- 21 u	- 91 u
After	39 u	39 u

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

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

65% = ⁶⁵₁₀₀ = ¹³₂₀
30% = ³⁰₁₀₀ = ³₁₀

The amounts of amount that Risa and Tim had left were the same. Make the numerators the same.

¹³₂₀ of Risa's amount = ³₁₀ of Tim's amount
³⁹₆₀ of Risa's amount = ³⁹₁₃₀ of Tim's amount

Amount that Risa had = 60 u

50% of the amount that Risa had
= 50% x 60 u
= ⁵⁰₁₀₀ x 60 u
= 30 u

Difference between Tim's amount and 50% of Risa's amount
= 130 u - 30 u
= 100 u

100 u = 2800

1 u = 2800 ÷ 100 = 28

Amount that Tim had at first
= 130 u
= 130 x 28
= $3640

Answer(s): $3640