The height (in centimeters) of a candle is a linear function

Last updated: 7/17/2022

The height (in centimeters) of a candle is a linear function of the amount of time (in hours) it has been burning. When graphed, the function gives a line with a slope of -0.3. See the figure below. Suppose that the height of the candle after 15 hours is 20.5 centimeters. What was the height of the candle after 6 hours?