### Home > MC2 > Chapter 6 > Lesson 6.2.5 > Problem6-118

6-118.

To find the best cost per square inch, we must first find the area of each pizza.

Using the formula for the area of a circle, r2π:
Medium pizza: 62π = 36π = 113.04 in2.
Large pizza: 92π = 81π = 254.34 in2.

Remember, 12 in. and 18 in. are the diameters of the pizzas.

Now with the area, we can determine the price per square inch of pizza. We can convert to cents for a better indicator of price.

Medium pizza: $10 = 1000 cents $\frac{1000\text{ cents}}{113.04\text{ in^2 }} \approx \text{9 cents per square inch}$ Large pizza:$16 = 1600 cents

$\frac{1600 \text{ cents}}{254.34 \text{ in^2}} \approx \text{6 cents per square inch}$