Sarah and three of her friends left her house for a long bike ride on the river bike path. They rode for three hours at $10$ miles per hour and then rested for an hour while they ate their lunches. After lunch, they raced each other back to Sarah’s house at $15$ miles per hour.

1. Draw a graph that could represent this situation. Place “Time (hours)” on the horizontal axis and “Distance (miles from Sarah’s house)” on the vertical axis.

   Hint (a):

   Recall the Distance = $\text{Rate} × \text{Time}$ formula.

   More Help (a):

   Make a table of values and graph the points.

2. Describe each part of the graph using the following words: linear, nonlinear, decreasing, increasing, and constant.

   Hint (b):

   Is there a constant slope?

   More Help (b):

   Does your graph have any ups and downs?