70% of Marion's amount was $506 more than Vaidev's amount. When Marion spent 60% of her amount and Vaidev spent 10% of his amount, they had the same amount of amount left. Find the amount that Vaidev had at first.

	70% of Marion's amount	Marion's amount	Vaidev's amount
Before	31.5 u	45 u	20 u
Change		- 27 u (- 60%)	- 2 u (- 10%)
After		18 u	18 u

Percentage of Marion's amount left
= 100% - 60%
= 40%

Percentage of Vaidev's amount left
= 100% - 10%
= 90%

40% = ⁴⁰₁₀₀ = ²₅
90% = ⁹⁰₁₀₀ = ⁹₁₀

The amounts of amount that Marion and Vaidev had left were the same.
Make the numerators the same.

²₅ of Marion's amount = ⁹₁₀ of Vaidev's amount
¹⁸₄₅ of Marion's amount = ¹⁸₂₀ of Vaidev's amount

Amount that Marion had = 45 u

70% of the amount that Marion had
= 45 u x 70%
= 45 u x ⁷⁰₁₀₀
= 31.5 u

Difference between 70% of Marion's amount and Vaidev's amount
= 31.5 u - 20 u 
= 11.5 u

11.5 u = 506
1 u = 506 ÷ 11.5 = 44

Amount that Vaidev had at first
= 20 u
= 20 x 44
= $880

Answer(s): $880