# How many people can be fed?

• Aug 29th 2010, 03:09 PM
hydride
How many people can be fed?
When sizes of pizzas are quoted in inches, the number quoted is the diameter of the pizza. A restaurant advertises an 8-http://session.masteringphysics.com/...B%5Crm+inch%7D "personal pizza." If this 8-http://session.masteringphysics.com/...B%5Crm+inch%7D pizza is the right size for one person, how many people can be fed by a large 16-http://session.masteringphysics.com/...B%5Crm+inch%7D pizza?

This is suppose to be simple, but i dont know why i am having trouble.(Crying)
• Aug 29th 2010, 03:22 PM
HallsofIvy
I presume that when feeding a number of people from a pizza, they will get "enough to eat" if they get the same area as from an 8 inch pizza.

The area of a circle is given by $\pi r^2= \frac{\pi}{4}d^2$. If you double the diameter of the circle what happens to the area?

(If you can't answer that directly, calculate the area with d= 8, and with d= 16, and compare those values.)
• Aug 29th 2010, 03:23 PM
hydride
Thank you! I found the answer!