Question

Royal Pizza's advertisement says that 10 pizzas will cost $120. How much will 1 pizza cost?

Answer 1

In order to find the cost of 1 pizza, let's use the following rule of three:

$\begin{gathered} 10\text{ pizzas}\to120 \\ 1\text{ pizza}\to x \\ \\ \frac{10}{1}=\frac{120}{x} \\ 10x=120 \\ x=\frac{120}{10} \\ x=12 \end{gathered}$

So the cost of one pizza is $12.