Oscar and Luis had 131 stickers in total. Luis had 77 stickers more than Oscar at first. After Oscar and Luis played a game with Cindy, Oscar had ²₉ as many stickers as Luis. If Oscar lost as many stickers as Luis to Cindy, find the number of stickers that Oscar lost to Cindy.

	Oscar	Luis	Difference
Before	1 u	1 u + 77	77
Change	- ?	- ?
After	2 p	9 p	7 p

Total number of stickers at first
= 1 u + 1 u + 77 
= 2 u + 77

2 u + 77 = 131
2 u = 131 - 77
2 u = 54

1 u = 54 ÷ 2 = 27

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

Difference in the number of stickers in the end
= 9 p - 2 p
= 7 p

7 p = 77

1 p = 77 ÷ 7 = 11

Number of stickers that Oscar lost to Cindy
= 1 u - 2 p
= 27 - 2 x 11
= 27 - 22
= 5

Answer(s): 5