Answer:
PS = 28 units.
Explanation:
See the attached diagram.
This is a figure of rectangle with length (3y + 3) and width 4y.
Now, the perimeter of the rectangle is 2[(3y + 3) + 4y] = 2(7y + 3)
The perimeter of the rectangle is given to be 104 units.
So, 2(7y + 3) = 104
⇒ 7y + 3 = 52
⇒ 7y = 49
⇒ y = 7
Therefore, PS = 4y = 4(7) = 28 units. (Answer)