Four students rode different buses to school, and each trip took 30 min

Question

. 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)
Responses

42 mi/h
42 miles per hour

16 mi/h
16 miles per hour

1.4 mi/h
1.4 miles per hour

21 mi/h

Answer 1

To find the average speed of the buses, we need to first calculate the total distance traveled and then use the total time to find the average speed.

1. Calculate the total distance:

   • One student rode 8 miles.
   • One student rode 10 miles.
   • Two students each rode 12 miles.

   \[ \text{Total distance} = 8 \text{ mi} + 10 \text{ mi} + 12 \text{ mi} + 12 \text{ mi} = 8 + 10 + 12 + 12 = 42 \text{ mi} \]

2. Calculate the total time: Each trip took 30 minutes, and there are 4 students. \[ \text{Total time} = 30 \text{ min} \times 4 = 120 \text{ min} = 2 \text{ hours} \]

3. Calculate the average speed: Average speed is calculated as total distance divided by total time. \[ \text{Average speed} = \frac{\text{Total distance}}{\text{Total time}} = \frac{42 \text{ mi}}{2 \text{ h}} = 21 \text{ mi/h} \]

Thus, the average speed of the buses is 21 mi/h.