Henry and Seth had 155 stickers in total. Seth had 81 stickers more than Henry at first. After Henry and Seth played a game with Gwen, Henry had ²₁₁ as many stickers as Seth. If Henry lost as many stickers as Seth to Gwen, find the number of stickers that Henry lost to Gwen.

	Henry	Seth	Difference
Before	1 u	1 u + 81	81
Change	- ?	- ?
After	2 p	11 p	9 p

Total number of stickers at first
= 1 u + 1 u + 81 
= 2 u + 81

2 u + 81 = 155
2 u = 155 - 81
2 u = 74

1 u = 74 ÷ 2 = 37

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

Difference in the number of stickers in the end
= 11 p - 2 p
= 9 p

9 p = 81

1 p = 81 ÷ 9 = 9

Number of stickers that Henry lost to Gwen
= 1 u - 2 p
= 37 - 2 x 9
= 37 - 18
= 19

Answer(s): 19