Lynn, Risa and Gem shared $580 among themselves. Risa and Gem shared ²₅ of the money equally. After Risa gave away some of her money to Lynn, Gem had 4 times as much money as Risa. How much money did Risa give to Lynn?

	Risa	Gem	Lynn	Total
Before	1x4 = 4 u	1x4 = 4 u	3x4 = 12 u	20 u
Change	- 3 u	No change	+ 3 u
After	1x1 = 1 u	4x1 = 4 u	15 u	20 u

Risa and Gem shared ²₅ of the money equally.

Fraction of the money that Risa and Gem each had
= ²₅ ÷ 2
= ²₅ x ¹₂
= ¹₅

The amount that Gem had remains unchanged.  The amount that Gem had is the unchanged quantity. Make the amount that Gem had the same. LCM of 1 and 4 is 4.

The amount that Risa and Gem had at first is the same.

Total amount that they had at first
= 4 u + 4 u + 12 u
= 20 u

20 u = 580

1 u = 580 ÷ 20 = 29

Amount that Risa gave to Lynn
= 4 u - 1 u
= 3 u
= 3 x 29
= $87

Answer(s): $87