Usha, Yoko and Min shared $315 among themselves. Yoko and Min shared ²₇ of the money equally. After Yoko gave away some of her money to Usha, Min had 3 times as much money as Yoko. How much money did Yoko give to Usha?

	Yoko	Min	Usha	Total
Before	1x3 = 3 u	1x3 = 3 u	5x3 = 15 u	21 u
Change	- 2 u	No change	+ 2 u
After	1x1 = 1 u	3x1 = 3 u	17 u	21 u

Yoko and Min shared ²₇ of the money equally.

Fraction of the money that Yoko and Min each had
= ²₇ ÷ 2
= ²₇ x ¹₂
= ¹₇

The amount that Min had remains unchanged.  The amount that Min had is the unchanged quantity. Make the amount that Min had the same. LCM of 1 and 3 is 3.

The amount that Yoko and Min had at first is the same.

Total amount that they had at first
= 3 u + 3 u + 15 u
= 21 u

21 u = 315

1 u = 315 ÷ 21 = 15

Amount that Yoko gave to Usha
= 3 u - 1 u
= 2 u
= 2 x 15
= $30

Answer(s): $30