Look at the line of the graph, and find a point that is easy to read. Points that are easy to read occur on the intersection of grid lines. Start from origin, point (0, 0), the bottom left, and go up to the right along the graph line. You will soon be at a point on the graph line that is at the intersection of the grid lines that correspond to 1 day (along the horizontal) and 3 chapters (along the vertical). From this information, you can calculate the slope or unit rate.
3 chapters in 1 day is a rate of 3 chapters per day.
Answer: C. 3 chapters per day
