Betty and Cindy had a total of 144 stamps. Cindy gave ¹₄ of her stamps to Betty. In return, Betty gave ¹₇ of the total number of stamps that she had to Cindy. In the end, each girl had the same number of stamps. How many stamps did Betty have at first?

	Betty	Cindy	Total
Before 1	?	4 u	144
Change 1	+ 1 u	- 1 u
After 1	84	3 u	144
Before 2	7 p	3 u	144
Change 2	- 1 p	+ 1 p
After 2	6 p (72)	72	144

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

Number of stamps that Cindy and Betty each had in the end is the same.

Number of stamps that Betty had in the end
= 144 ÷ 2
= 72

Number of stamps that Betty had in the end = 6 p

6 p = 72

1 p = 72 ÷ 6 = 12

Number of stamps that Betty had after receiving some stamps from Cindy
= 7 p
= 7 x 12
= 84

Number of stamps that Cindy had after giving to Betty
= 144 - 84
= 60

3 u = 60

1 u = 60 ÷ 3 = 20

Number of stamps that Cindy had at first
= 4 u
= 4 x 20
= 80

Number of stamps that Betty had at first
= 144 - 80
= 64

Answer(s): 64