Julie and Xylia have some biscuits each. If Julie gives Xylia 21 biscuits, Julie will have ²₉ as many biscuits as Xylia. If Julie gives Xylia 11 biscuits, they will have an equal number of biscuits. How many biscuits does Julie have at first?

	Case 1		Case 2
	Julie	Xylia	Julie	Xylia
Before	2 u + 21	9 u - 21	5.5 u + 11	5.5 u - 11
Change	- 21	+ 21	- 11	+ 11
After	2 u	9 u	5.5 u	5.5 u

Total number of biscuits that Julie and Xylia have
= 2 u + 9 u
= 11 u 

Number of biscuits that Julie and Xylia each has in the end is the same.

Number of biscuits that Julie and Xylia each has in the end in Case 2
= 11 u ÷ 2
= 5.5 u

Number of biscuits that Julie had at first is the same in Case 1 and Case 2.

5.5 u + 11 = 2 u + 21
5.5 u - 2 u = 21 - 11
0.5 u = 10

1 u = 10 ÷ 0.5 = 20

Number of biscuits that Julie has
= 2 u + 21
= 2 x 20 + 21
= 40 + 21
= 61

Answer(s): 61