To find out how many miles the whale swims in 16 days, we can first determine its daily swimming rate.
The whale swims 200 miles in 5 days, so its daily rate is:
\[ \text{Daily Rate} = \frac{200 \text{ miles}}{5 \text{ days}} = 40 \text{ miles per day} \]
Now, to find the distance it swims in 16 days, we can multiply the daily rate by the number of days:
\[ \text{Distance in 16 days} = 40 \text{ miles per day} \times 16 \text{ days} = 640 \text{ miles} \]
Thus, the correct equation to find how many miles it swims in 16 days is:
\[ y = 40 \times 16 \]
So the answer is:
y = 40 × 16