Risa and Esther had a total of 70 stamps. Esther gave ¹₆ of her stamps to Risa. In return, Risa gave ¹₈ of the total number of stamps that she had to Esther. In the end, each girl had the same number of stamps. How many stamps did Risa have at first?

	Risa	Esther	Total
Before 1	?	6 u	70
Change 1	+ 1 u	- 1 u
After 1	40	5 u	70
Before 2	8 p	5 u	70
Change 2	- 1 p	+ 1 p
After 2	7 p (35)	35	70

Since Esther gave some stamps to Risa and Risa then gave some stamps to Esther, it is an internal transfer of stamps between the two girls. So, the total number of stamps remains unchanged.

Number of stamps that Esther and Risa each had in the end is the same.

Number of stamps that Risa had in the end
= 70 ÷ 2
= 35

Number of stamps that Risa had in the end = 7 p

7 p = 35

1 p = 35 ÷ 7 = 5

Number of stamps that Risa had after receiving some stamps from Esther
= 8 p
= 8 x 5
= 40

Number of stamps that Esther had after giving to Risa
= 70 - 40
= 30

5 u = 30

1 u = 30 ÷ 5 = 6

Number of stamps that Esther had at first
= 6 u
= 6 x 6
= 36

Number of stamps that Risa had at first
= 70 - 36
= 34

Answer(s): 34