To find out how long it will take Francesca to ride 8 miles today, we first need to determine her riding rate based on her performance yesterday.
Yesterday, Francesca rode 6 miles in 30 minutes. We can calculate her riding rate using the following formula:
\[ \text{Rate} = \frac{\text{Distance}}{\text{Time}} = \frac{6 \text{ miles}}{30 \text{ minutes}} = \frac{1}{5} \text{ miles per minute} \]
Next, we need to determine how long it will take her to ride 8 miles at this rate. Using the formula for time, we have:
\[ \text{Time} = \frac{\text{Distance}}{\text{Rate}} \]
Substituting in her distance for today and her rate:
\[ \text{Time} = \frac{8 \text{ miles}}{\frac{1}{5} \text{ miles per minute}} = 8 \text{ miles} \times 5 \text{ minutes per mile} = 40 \text{ minutes} \]
Therefore, it will take Francesca 40 minutes to ride 8 miles today.