To find the rate and the unit rate of 15 chapters in 5 days, we can break it down as follows:
Rate: This is simply the quantity divided by the time it takes. In this case, the rate of chapters per day is:
\[ \text{Rate} = \frac{15 \text{ chapters}}{5 \text{ days}} = 3 \text{ chapters per day} \]
Unit Rate: This is the same as the rate but expressed in terms of one unit of time. Therefore, the unit rate is again:
\[ \text{Unit Rate} = 3 \text{ chapters per day} \]
So both the rate and the unit rate are 3 chapters per day.