1. **Problem Statement:** We are given a graph showing the inches of snow on the ground over time during a snowstorm. The snow falls at a constant rate for some hours, then stops, then falls again at a different rate. We need to find after how many hours there were 7 inches of snow on the ground. 2. **Understanding the Graph:** The graph shows three segments: - From about 0 to 3 hours, snow increases from 2 to 5 inches. - From 3 to 8 hours, the snow remains constant at 5 inches (no snowfall). - From 8 to 15 hours, snow increases from 5 to 7 inches. 3. **Key Observations:** - The snow reaches 5 inches at 3 hours and stays at 5 inches until 8 hours. - After 8 hours, snow starts increasing again until it reaches 7 inches at some time between 8 and 15 hours. 4. **Calculate the rate of snowfall in the last segment:** - Snow increases from 5 inches to 7 inches over the time interval from 8 to 15 hours. - Duration of this interval: $15 - 8 = 7$ hours. - Increase in snow: $7 - 5 = 2$ inches. - Rate of snowfall in this segment: $$\frac{2 \text{ inches}}{7 \text{ hours}} = \frac{2}{7} \text{ inches per hour}.$$ 5. **Find the time when snow reaches 7 inches:** - Let $t$ be the time in hours after the storm began when snow reaches 7 inches. - Since snow is 5 inches at 8 hours, the additional snow after 8 hours is $7 - 5 = 2$ inches. - Using the rate, time to accumulate 2 inches after 8 hours is $$\frac{2 \text{ inches}}{\frac{2}{7} \text{ inches/hour}} = 7 \text{ hours}.$$ - Therefore, $$t = 8 + 7 = 15 \text{ hours}.$$ 6. **Answer:** There were 7 inches of snow on the ground after 15 hours.