I think it's like 2.739 × 10
A circle is a collection of points all of which are on the circumference of the circle. If you use algebra and (x-h)^2 + (y-k)^2 = r^2 and the info contained in the coordinates (x,y) of each city, you can find h, k and r. Then r is the (equal) distance between each city and the center of the circle, where the new tower will be built.
You can find 15 DVDs.
165 divided by 11 = 15
I can help you with 11 so its 588 because I know that 600 divide by 12 equals 50 so they said they want less then 600 so I tried 49 times 12 equals 588