Sabrina and Barbara had a total of 40 stickers. Barbara gave ¹₃ of her stickers to Sabrina. In return, Sabrina gave ¹₆ of the total number of stickers that she had to Barbara. In the end, each girl had the same number of stickers. How many stickers did Sabrina have at first?

	Sabrina	Barbara	Total
Before 1	?	3 u	40
Change 1	+ 1 u	- 1 u
After 1	24	2 u	40
Before 2	6 p	2 u	40
Change 2	- 1 p	+ 1 p
After 2	5 p (20)	20	40

Since Barbara gave some stickers to Sabrina and Sabrina then gave some stickers to Barbara, it is an internal transfer of stickers between the two girls. So, the total number of stickers remains unchanged.

Number of stickers that Barbara and Sabrina each had in the end is the same.

Number of stickers that Sabrina had in the end
= 40 ÷ 2
= 20

Number of stickers that Sabrina had in the end = 5 p

5 p = 20

1 p = 20 ÷ 5 = 4

Number of stickers that Sabrina had after receiving some stickers from Barbara
= 6 p
= 6 x 4
= 24

Number of stickers that Barbara had after giving to Sabrina
= 40 - 24
= 16

2 u = 16

1 u = 16 ÷ 2 = 8

Number of stickers that Barbara had at first
= 3 u
= 3 x 8
= 24

Number of stickers that Sabrina had at first
= 40 - 24
= 16

Answer(s): 16