# RE1 | moonshotai/kimi-k3 | run 1

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

## Work

**Step 1: Find the total distance.**

\[ 240 + 180 = 420 \text{ miles} \]

**Step 2: Find the total time.**

\[ 3 + 2 = 5 \text{ hours} \]

**Step 3: Divide total distance by total time.**

\[ \text{Average speed} = \frac{420 \text{ miles}}{5 \text{ hours}} = 84 \text{ mph} \]

Note that simply averaging the two segment speeds (80 mph and 90 mph) would give 85 mph, which is incorrect because the train spent different amounts of time at each speed.

Would you like to see how this changes if the train traveled each segment for equal times instead of equal distances?
