Mark and Peter had 52 stickers in total. Mark had 8 stickers less than Peter at first. After Mark and Peter played a game with Jean, Mark had ¹₃ as many stickers as Peter. If Mark lost as many stickers as Peter to Jean, find the number of stickers that Peter lost to Jean.

	Mark	Peter	Difference
Before	1 u	1 u + 8	8
Change	- ?	- ?
After	1 p	3 p	2 p

Total number of stickers at first
= 1 u + 1 u + 8 
= 2 u + 8

2 u + 8 = 52
2 u = 52 - 8
2 u = 44

1 u = 44 ÷ 2 = 22

Since Mark lost the same number of stickers as Peter, the difference in the number of stickers between Mark and Peter at first and in the end remains the same.

Difference in the number of stickers in the end
= 3 p - 1 p
= 2 p

2 p = 8

1 p = 8 ÷ 2 = 4

Number of stickers that Mark lost to Jean
= 1 u - 1 p
= 22 - 1 x 4
= 22 - 4
= 18

Since Peter lost the same number of stickers as Mark, the number of stickers that each lost to Jean is the same.

Number of stickers that Peter lost = 18

Answer(s): 18