Caden had an equal number of chocolate biscuits, blueberry biscuits and butter biscuits. After he ate 43 chocolate biscuits, some blueberry biscuits and butter biscuits, there were 62 biscuits left. The number of blueberry biscuits he ate was twice the number of butter biscuits he ate. The number of blueberry biscuits left was 21 more than the number of chocolate biscuits left. How many chocolate biscuits were there at first?

	Chocolate biscuits	Blueberry biscuits	Butter biscuits	Total biscuits
Before	1 p + 43	1 p + 2 u + 21	1 p + 2 u + 21
Change	- 43	- 2 u	- 1 u
After	1 p	1 p + 21	1 p + 21 + 1 u	62

Number of blueberry biscuits and chocolate biscuits was equal at first.

1 p + 2 u + 21 = 1 p + 43
2 u = 43 - 21
2 u = 22

1 u = 22 ÷ 2 = 11

Total number of biscuits in the end
= 1 p + 1 p + 21 + 1 p + 21 + 11
= 1 p + 1 p + 1 p + 21 + 21 + 11
= 3 p + 53

3 p + 53 = 62
3 p = 62 - 53
3 p = 9

1 p = 9 ÷ 3 = 3

Number of chocolate biscuits at first
= 1 p + 43
= 3 + 43
= 46

Answer(s): 46