80% of Erika's amount was $494 more than Mark's amount. When Erika spent 55% of her amount and Mark spent 20% of his amount, they had the same amount of amount left. Find the amount that Mark had at first.

	80% of Erika's amount	Erika's amount	Mark's amount
Before	64 u	80 u	45 u
Change		- 44 u (- 55%)	- 9 u (- 20%)
After		36 u	36 u

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

Percentage of Mark's amount left
= 100% - 20%
= 80%

45% = ⁴⁵₁₀₀ = ⁹₂₀
80% = ⁸⁰₁₀₀ = ⁴₅

The amounts of amount that Erika and Mark had left were the same.
Make the numerators the same.

⁹₂₀ of Erika's amount = ⁴₅ of Mark's amount
³⁶₈₀ of Erika's amount = ³⁶₄₅ of Mark's amount

Amount that Erika had = 80 u

80% of the amount that Erika had
= 80 u x 80%
= 80 u x ⁸⁰₁₀₀
= 64 u

Difference between 80% of Erika's amount and Mark's amount
= 64 u - 45 u 
= 19 u

19 u = 494
1 u = 494 ÷ 19 = 26

Amount that Mark had at first
= 45 u
= 45 x 26
= $1170

Answer(s): $1170