Pierre had an equal number of butter puffs, vanila puffs and cream puffs. After he ate 35 butter puffs, some vanila puffs and cream puffs, there were 63 puffs left. The number of vanila puffs he ate was thrice the number of cream puffs he ate. The number of vanila puffs left was 20 more than the number of butter puffs left. How many butter puffs were there at first?

	Butter puffs	Vanila puffs	Cream puffs	Total puffs
Before	1 p + 35	1 p + 3 u + 20	1 p + 3 u + 20
Change	- 35	- 3 u	- 1 u
After	1 p	1 p + 20	1 p + 20 + 1 u	63

Number of vanila puffs and butter puffs was equal at first.

1 p + 3 u + 20 = 1 p + 35
3 u = 35 - 20
3 u = 15

1 u = 15 ÷ 3 = 5

Total number of puffs in the end
= 1 p + 1 p + 20 + 1 p + 20 + 5
= 1 p + 1 p + 1 p + 20 + 20 + 5
= 3 p + 45

3 p + 45 = 63
3 p = 63 - 45
3 p = 18

1 p = 18 ÷ 3 = 6

Number of butter puffs at first
= 1 p + 35
= 6 + 35
= 41

Answer(s): 41