Erika and Min had a total of 84 stickers. Min gave ¹₃ of her stickers to Erika. In return, Erika gave ¹₈ of the total number of stickers that she had to Min. In the end, each girl had the same number of stickers. How many stickers did Erika have at first?

	Erika	Min	Total
Before 1	?	3 u	84
Change 1	+ 1 u	- 1 u
After 1	48	2 u	84
Before 2	8 p	2 u	84
Change 2	- 1 p	+ 1 p
After 2	7 p (42)	42	84

Since Min gave some stickers to Erika and Erika then gave some stickers to Min, it is an internal transfer of stickers between the two girls. So, the total number of stickers remains unchanged.

Number of stickers that Min and Erika each had in the end is the same.

Number of stickers that Erika had in the end
= 84 ÷ 2
= 42

Number of stickers that Erika had in the end = 7 p

7 p = 42

1 p = 42 ÷ 7 = 6

Number of stickers that Erika had after receiving some stickers from Min
= 8 p
= 8 x 6
= 48

Number of stickers that Min had after giving to Erika
= 84 - 48
= 36

2 u = 36

1 u = 36 ÷ 2 = 18

Number of stickers that Min had at first
= 3 u
= 3 x 18
= 54

Number of stickers that Erika had at first
= 84 - 54
= 30

Answer(s): 30