Question

1. unit rate (money per hour)

$30 for 2½ hours.
a. $10
b. $11
c. $12
d. $15
answer: ____________

Explanation:

Step1: Recall Unit Rate Formula

Unit rate (money per hour) is total money divided by total hours. So formula is $r = \frac{\text{Total Money}}{\text{Total Hours}}$.

Step2: Convert Mixed Number to Decimal

$2\frac{1}{2}$ hours is equal to $2.5$ hours (since $\frac{1}{2}=0.5$).

Step3: Calculate Unit Rate

Substitute total money = $\$30$ and total hours = $2.5$ into the formula: $r=\frac{30}{2.5}$.
Dividing 30 by 2.5: $30\div2.5 = 12$. So the unit rate is $\$12$ per hour.

Answer:

C. $12$