Question

Four students rode different buses to school, and each trip took 30 min . One student rode 8 mi , one rode 10 mi , and the other two each rode 12 mi . What was the average speed of the buses?(1 point) 16 mi/h 16 miles per hour 42 mi/h 42 miles per hour 1.4 mi/h 1.4 miles per hour 21 mi/h

Answer 1

To calculate the average speed of the buses, we'll use the formula for speed:

\[
\text{Speed} = \frac{\text{Distance}}{\text{Time}}
\]

### Step 1: Calculate the total distance traveled by all students.
The distances for the students are:
- One student rode 8 miles.
- One student rode 10 miles.
- Two students rode 12 miles each.

Calculating the total distance:

\[
\text{Total Distance} = 8 + 10 + 12 + 12 = 42 \text{ miles}
\]

### Step 2: Determine the total time taken for all students.
Each trip took 30 minutes, which we can convert to hours:

\[
30 \text{ minutes} = \frac{30}{60} \text{ hours} = 0.5 \text{ hours}
\]

Since there are four students, the total time for all students is:

\[
\text{Total Time} = 0.5 \text{ hours} \times 4 = 2 \text{ hours}
\]

### Step 3: Calculate the average speed of the buses.
Now, we can calculate the average speed using the total distance and total time:

\[
\text{Average Speed} = \frac{\text{Total Distance}}{\text{Total Time}} = \frac{42 \text{ miles}}{2 \text{ hours}} = 21 \text{ mi/h}
\]

Thus, the average speed of the buses is **21 miles per hour**.