Caroline can sketch 8 cartoon strips in ten hours. How long will it take her to sketch 16 ​strips?

First, we need to determine Caroline's rate of sketching cartoon strips. She can sketch 8 cartoon strips in 10 hours. To find her rate, we divide the number of strips by the time taken:

\[ \text{Rate} = \frac{8 \text{ strips}}{10 \text{ hours}} = 0.8 \text{ strips per hour} \]

Next, we want to find out how long it will take her to sketch 16 strips. We can use her rate to calculate the time needed:

\[ \text{Time} = \frac{\text{Number of strips}}{\text{Rate}} = \frac{16 \text{ strips}}{0.8 \text{ strips per hour}} \]

Calculating this gives:

\[ \text{Time} = 20 \text{ hours} \]

So, it will take Caroline 20 hours to sketch 16 strips.