First, find the area for the kitchen floor: 16.5*15=247.5 squared feet
Then find the area for one tile: 0.5*0.5=0.25 squared feet
Finally, divide the mayor area between the minor: 247.5/0.25= 990 tiles.
Also you can do it in this another way:
First, divide length of the kitchen floor between the length of one tile: 16.5/0.5=33
Then, do the same for the height: 15/0.5=30
Finally multyply both results: 33*30= 990 tiles.
We need to find the center and the radius of

The general circle equation is the following

where
(h,k) is the center and
r is the radius
1. rearrange the equation

2. Add 25 on both sides

3. Factor

Now we have an equation that is very similar to the circle equation, so let's compare them
Center -> (h,k) = (5,-11)
radius -> r = 5
3/4 in = 6 mi
? In = 32 miles
32 * 0.74 / 6 = 4 in
The distance apart is 4 in