Jeremy had an equal number of strawberry doughnuts, cream doughnuts and matcha doughnuts. After he ate 31 strawberry doughnuts, some cream doughnuts and matcha doughnuts, there were 46 doughnuts left. The number of cream doughnuts he ate was thrice the number of matcha doughnuts he ate. The number of cream doughnuts left was 16 more than the number of strawberry doughnuts left. How many strawberry doughnuts were there at first?

	Strawberry doughnuts	Cream doughnuts	Matcha doughnuts	Total doughnuts
Before	1 p + 31	1 p + 3 u + 16	1 p + 3 u + 16
Change	- 31	- 3 u	- 1 u
After	1 p	1 p + 16	1 p + 16 + 1 u	46

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

1 p + 3 u + 16 = 1 p + 31
3 u = 31 - 16
3 u = 15

1 u = 15 ÷ 3 = 5

Total number of doughnuts in the end
= 1 p + 1 p + 16 + 1 p + 16 + 5
= 1 p + 1 p + 1 p + 16 + 16 + 5
= 3 p + 37

3 p + 37 = 46
3 p = 46 - 37
3 p = 9

1 p = 9 ÷ 3 = 3

Number of strawberry doughnuts at first
= 1 p + 31
= 3 + 31
= 34

Answer(s): 34