Rate is a ratio that compares two quantities of different units.
I'm not sure about the blanks of the Unit rate, but I do know it a comparison of two different quantities when they are put together.
I'm really sorry about that.
Since Circumference is

So to get Area, you have to get the radius first:

, which is

Next we divide both sides by

to get:

Now we have to get the area which is

Plug in 15 for r, you should get
Final Answer:
Rachel is taller, she is taller by 23 cm
That should be 1,000 MILLILITER bag.
1,000 ml per 8 hours =
125 ml per hour