Question

At a pizza restaurant, a personal pizza has a radius of 10 centimeters and costs $5. Another restaurant takes a pizza with radius 30 centimeters, cuts it into 8 slices of equal area, and charges $5 per slice. Which is a better deal? Explain your reasoning.

Answer 1

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.