The slope of a line is determined by the formula:

$\text{slope} = \frac{\Delta y}{\Delta x}$

From the graph:

• The $y$-axis represents "Distance (miles)".
• The $x$-axis represents "Time (hours)".
• At the point (0, 0), distance is 0 miles at 0 hours.
• At the point (3, 60), distance is 60 miles at 3 hours.

Calculating the slope: $\text{slope} = \frac{60 - 0}{3 - 0} = \frac{60}{3} = 20 \, \text{miles per hour (mi/h)}.$

Thus, the correct answer is:

20 mi/h.

Would you like me to provide more details or explore a related topic?

Here are 5 related questions to consider:

1. How do you calculate slope from a table of values?
2. What are real-world examples of interpreting slopes?
3. How does the slope change if the line is steeper or less steep?
4. What is the meaning of a zero slope in a distance-time graph?
5. How can you determine the slope if the graph scales change?

Tip: Always check units (e.g., miles, hours) when interpreting graphs!