Three girls used the same number of small pebbles to make necklaces. Sarah used ³₅ of her small pebbles, Emma used ⁴₅ of hers and Abi used ²₃ of hers. They had a total of 318 small pebbles at first. How many small pebbles did each girl use?
Make the numerators the same.   

LCM of 3, 4 and 2 = 12

³₅ Sarah's small pebbles = ⁴₅ Emma's small pebbles = ²₃ Abi's small pebbles
^3x4_5x4 Sarah's small pebbles = ^4x3_5x3 Emma's small pebbles = ^2x6_3x6 Abi's small pebbles
¹²₂₀ Sarah's small pebbles = ¹²₁₅ Emma's small pebbles = ¹²₁₈ Abi's small pebbles

	Sarah	Emma	Abi
Before	20 u	15 u	18 u
Change	- 12 u	- 12 u	- 12 u
After	8 u	3 u	6 u

Total number of small pebbles at first
= 20 u + 15 u + 18 u
= 53 u

53 u = 318

1 u = 318 ÷ 53 = 6

Number of small pebbles that each girl used
= 12 u
= 12 x 6
= 72

Answer(s): 72