# RE1 | meta/muse-spark-1.1 | run 2

## Prompt

A train travels 240 miles in 3 hours, then 180 miles in 2 hours. What is its average speed for the entire trip? Show your work.

## Response

The train's average speed for the entire trip is **84 miles per hour**.

Average speed is total distance divided by total time, not the average of the two speeds.

## Step-by-Step Calculation

**1. Total Distance**
\[ 240 \text{ miles} + 180 \text{ miles} = 420 \text{ miles} \]

**2. Total Time**
\[ 3 \text{ hours} + 2 \text{ hours} = 5 \text{ hours} \]

**3. Average Speed Formula**
\[ \text{Average Speed} = \frac{\text{Total Distance}}{\text{Total Time}} \]

\[ \text{Average Speed} = \frac{420}{5} = 84 \]

Therefore, the average speed is 84 mph.

Note: This is not simply \((80 + 90)/2 = 85\) mph, because the time spent at each speed is different. You must weight by total distance and total time.

Want me to calculate the average speed if the train adds another leg to the trip?
