Albert had an equal number of matcha biscuits, cream biscuits and blueberry biscuits. After he ate 25 matcha biscuits, some cream biscuits and blueberry biscuits, there were 51 biscuits left. The number of cream biscuits he ate was four times the number of blueberry biscuits he ate. The number of cream biscuits left was 17 more than the number of matcha biscuits left. How many matcha biscuits were there at first?

	Matcha biscuits	Cream biscuits	Blueberry biscuits	Total biscuits
Before	1 p + 25	1 p + 4 u + 17	1 p + 4 u + 17
Change	- 25	- 4 u	- 1 u
After	1 p	1 p + 17	1 p + 17 + 1 u	51

Number of cream biscuits and matcha biscuits was equal at first.

1 p + 4 u + 17 = 1 p + 25
4 u = 25 - 17
4 u = 8

1 u = 8 ÷ 4 = 2

Total number of biscuits in the end
= 1 p + 1 p + 17 + 1 p + 17 + 2
= 1 p + 1 p + 1 p + 17 + 17 + 2
= 3 p + 36

3 p + 36 = 51
3 p = 51 - 36
3 p = 15

1 p = 15 ÷ 3 = 5

Number of matcha biscuits at first
= 1 p + 25
= 5 + 25
= 30

Answer(s): 30