Opal had $1001 less than Eric. Opal spent ¹₇ of her money and Eric spent ²₃ of his money. In the end, Eric and Opal had the same amount of money left. Find the amount of money Eric had at first.

	Opal	Eric	Difference
Before	7x1 = 7 u	3x6 = 18 u	11 u
Change	- 1x1 = - 1 u	- 2x6 = - 12 u
After	6x1 = 6 u	1x6 = 6 u

Fraction of Opal's money left
= 1 - ¹₇
= ⁶₇

Fraction of Eric's money left
= 1 - ²₃
= ¹₃

Eric and Opal had the same amount of money in the end. Make the numerators the same. LCM of 6 and 1 is 6.

⁶₇ of Opal's money = ¹₃ of Eric's money
⁶₇ of Opal's money = ⁶₁₈ of Eric's money

Amount that Opal had at first = 7 u
Amount that Eric had at first = 18 u

Amount that Opal had less than Eric had at first
= 18 u - 7 u
= 11 u

11 u = 1001

1 u = 1001 ÷ 11 = 91

Amount that Eric had at first
= 18 u
= 18 x 91
= $1638

Answer(s): $1638