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

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

Number of pens that Sabrina and Hazel each had in the end is the same.

Number of pens that Hazel had in the end
= 144 ÷ 2
= 72

Number of pens that Hazel had in the end = 6 p

6 p = 72

1 p = 72 ÷ 6 = 12

Number of pens that Hazel had after receiving some pens from Sabrina
= 7 p
= 7 x 12
= 84

Number of pens that Sabrina had after giving to Hazel
= 144 - 84
= 60

3 u = 60

1 u = 60 ÷ 3 = 20

Number of pens that Sabrina had at first
= 4 u
= 4 x 20
= 80

Number of pens that Hazel had at first
= 144 - 80
= 64

Answer(s): 64