Answer:
Remember that the area of a circle of radius R is given by:
A = pi*R^2
pi = 3.14
We know that:
Personal Pizza: radius = 10cm
price = $5
The area of pizza that you are getting is:
A = 3.14*(10cm)^2 = 314 cm^2
In the other case, we have a pizza with radius of 30 cm, cutted into 8 slices, such that each slice costs $5.
Then, if yo pay $5, the area of pizza that you get is an eight of the area of a circle of radius 30cm
This is:
A' = (1/8)*(3.14*(30cm)^2) = 353.25 cm^2
We can see that in the second case the area is larger, then the second option is the better deal, as you are getting a larger pizza area for the same price.
