To determine the equation that could be used to find how many miles a whale swims in 16 days, we first need to calculate the whale's daily swimming distance.
The whale swims 200 miles in 5 days, so we can find the daily distance by dividing the total distance by the number of days:
\[ \text{Daily Distance} = \frac{200 \text{ miles}}{5 \text{ days}} = 40 \text{ miles per day} \]
Now, to find out how far the whale swims in 16 days, we multiply the daily distance by 16:
\[ \text{Distance in 16 days} = 40 \text{ miles per day} \times 16 \text{ days} = 640 \text{ miles} \]
So the correct equation to find how many miles it swims in 16 days is:
\[ y = 40 \times 16 \]
Thus, the correct response is:
y = 40 × 16