Answer
$15$ cans
Work Step by Step
Since each serving needs $8$ ounces of lemonade, then the total ounces of lemonade needed for $120$ servings is
$$
8\times120=960\text{ ounces}
.$$
Since each can of $12$-ounce lemonade makes $64$ ounces of lemonade, then the number of cans of lemonade needed is
$$\begin{aligned}
&
960\text{ ounces} \div \frac{64\text{ ounces}}{\text{can}}
\\&=
960\text{ ounces} \times \frac{\text{can}}{64\text{ ounces}}
\\&=
15\text{ cans}
.\end{aligned}
$$
Hence, $15$ cans are needed for the $120$ servings.
