Mario's:
8 slices with an area of 14.13
8 * 14.13 = 113.04
So the area of the whole pizza is 113.04
Area of a Circle:
A = pi * r^2
113.04 = 3.14 * r^2
113.04 = 3.14r^2
36 = r^2
r = 6
So the radius is 6, now plug it in the formula for the circumference of a circle:
C = 2 * pi * r
C = 2 * 3.14 * 6
C = 37.68
Tito's:
16 slices with an area of 12.56
16 * 12.56 = 200.96
So the area of the whole pizza is 200.96.
A = pi * r^2
200.96 = 3.14 * r^2
200.96 = 3.14r^2
64 = r^2
r = 8
So the radius is 8, now plug it in the formula for the circumference of a circle.
C = 2 * pi * r
C = 2 * 3.14 * 8
C = 50.24
Peter's:
10 slices with an area of 15.386 each
10 * 15.386 = 153.86
So the total area is 153.86
A = pi * r^2
153.86 = 3.14 * r^2
153.86 = 3.14r^2
49 = r^2
r = 7
So this is the radius, now plug it into the formula for the circumference of a circle:
C = 2 * pi * r
C = 2 * 3.14 * 7
C = 43.96
So Mario's had the smallest circumference, then Peter's, then Tito's.
So your answer is correct.
For the 2nd question:
We can set up a proportion:
30/3 = x/264
Multiply 264 to both sides:
x = 264 * 30/3
x = 7920/3
x = 2640
So your answer was incorrect.