Three girls used the same number of smoothed stones to make bracelets. Yen used ³₅ of her smoothed stones, Yoko used ²₅ of hers and Erika used ²₃ of hers. They had a total of 102 smoothed stones at first. How many smoothed stones did each girl use?
Make the numerators the same.   

LCM of 3, 2 and 2 = 6

³₅ Yen's smoothed stones = ²₅ Yoko's smoothed stones = ²₃ Erika's smoothed stones
^3x2_5x2 Yen's smoothed stones = ^2x3_5x3 Yoko's smoothed stones = ^2x3_3x3 Erika's smoothed stones
⁶₁₀ Yen's smoothed stones = ⁶₁₅ Yoko's smoothed stones = ⁶₉ Erika's smoothed stones

	Yen	Yoko	Erika
Before	10 u	15 u	9 u
Change	- 6 u	- 6 u	- 6 u
After	4 u	9 u	3 u

Total number of smoothed stones at first
= 10 u + 15 u + 9 u
= 34 u

34 u = 102

1 u = 102 ÷ 34 = 3

Number of smoothed stones that each girl used
= 6 u
= 6 x 3
= 18

Answer(s): 18