Andy had an equal number of cream muffins, blueberry muffins and butter muffins. After he ate 30 cream muffins, some blueberry muffins and butter muffins, there were 66 muffins left. The number of blueberry muffins he ate was twice the number of butter muffins he ate. The number of blueberry muffins left was 18 more than the number of cream muffins left. How many cream muffins were there at first?

	Cream muffins	Blueberry muffins	Butter muffins	Total muffins
Before	1 p + 30	1 p + 2 u + 18	1 p + 2 u + 18
Change	- 30	- 2 u	- 1 u
After	1 p	1 p + 18	1 p + 18 + 1 u	66

Number of blueberry muffins and cream muffins was equal at first.

1 p + 2 u + 18 = 1 p + 30
2 u = 30 - 18
2 u = 12

1 u = 12 ÷ 2 = 6

Total number of muffins in the end
= 1 p + 1 p + 18 + 1 p + 18 + 6
= 1 p + 1 p + 1 p + 18 + 18 + 6
= 3 p + 42

3 p + 42 = 66
3 p = 66 - 42
3 p = 24

1 p = 24 ÷ 3 = 8

Number of cream muffins at first
= 1 p + 30
= 8 + 30
= 38

Answer(s): 38