Final answer:
Kirstin can arrange her photographs in a total of 16 rows, with 4 photographs per row. This arrangement uses the greatest common divisor of the number of family and friend photographs she has.
Step-by-step explanation:
To find out how Kirstin can arrange her photographs, we need to look for the greatest common divisor (GCD) of the number of family photographs and friend photographs, since she wants the same number of photographs in each row and wants to have separate rows for family and friends. The GCD of 36 (family photographs) and 28 (friend photographs) is 4. This tells us the greatest number of photographs we can have in each row while being able to divide both sets of photographs evenly into rows.
Now let's calculate the total number of rows:
- For family photographs: 36 photographs ÷ 4 photographs per row = 9 rows
- For friend photographs: 28 photographs ÷ 4 photographs per row = 7 rows
Therefore, Kirstin will need a total of 16 rows to arrange all her photographs (9 rows of family and 7 rows of friends).
As for the number of photographs in each row, she can fit 4 photographs per row which is the greatest common divisor we found earlier.