Ken had an equal number of strawberry doughnuts, chocolate doughnuts and butter doughnuts. After he ate 66 strawberry doughnuts, some chocolate doughnuts and butter doughnuts, there were 88 doughnuts left. The number of chocolate doughnuts he ate was four times the number of butter doughnuts he ate. The number of chocolate doughnuts left was 22 more than the number of strawberry doughnuts left. How many strawberry doughnuts were there at first?

	Strawberry doughnuts	Chocolate doughnuts	Butter doughnuts	Total doughnuts
Before	1 p + 66	1 p + 4 u + 22	1 p + 4 u + 22
Change	- 66	- 4 u	- 1 u
After	1 p	1 p + 22	1 p + 22 + 1 u	88

Number of chocolate doughnuts and strawberry doughnuts was equal at first.

1 p + 4 u + 22 = 1 p + 66
4 u = 66 - 22
4 u = 44

1 u = 44 ÷ 4 = 11

Total number of doughnuts in the end
= 1 p + 1 p + 22 + 1 p + 22 + 11
= 1 p + 1 p + 1 p + 22 + 22 + 11
= 3 p + 55

3 p + 55 = 88
3 p = 88 - 55
3 p = 33

1 p = 33 ÷ 3 = 11

Number of strawberry doughnuts at first
= 1 p + 66
= 11 + 66
= 77

Answer(s): 77