Luke and Lee had 105 stickers in total. Lee had 49 stickers more than Luke at first. After Luke and Lee played a game with Elyse, Luke had ¹₈ as many stickers as Lee. If Luke lost as many stickers as Lee to Elyse, find the number of stickers that Luke lost to Elyse.

	Luke	Lee	Difference
Before	1 u	1 u + 49	49
Change	- ?	- ?
After	1 p	8 p	7 p

Total number of stickers at first
= 1 u + 1 u + 49 
= 2 u + 49

2 u + 49 = 105
2 u = 105 - 49
2 u = 56

1 u = 56 ÷ 2 = 28

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

Difference in the number of stickers in the end
= 8 p - 1 p
= 7 p

7 p = 49

1 p = 49 ÷ 7 = 7

Number of stickers that Luke lost to Elyse
= 1 u - 1 p
= 28 - 1 x 7
= 28 - 7
= 21

Answer(s): 21