A ferry traveled 1/6 of the distance between two ports in 3/7. The ferry travels at a constant rate. At this rate, what fraction of the distance between the two ports can the ferry travel in one hour?

\dfrac{3}{7} \text { of an hour = } \dfrac{1}{6} \text { of the journey}

To find 1 hour, divide both side of the equation by 3/7:

\text {1 hour = } \dfrac{1}{6} \div \dfrac{3}{7} \text { of the journey}

\text {1 hour = } \dfrac{1}{6} \times \dfrac{7}{3} \text { of the journey}

\text {1 hour = } \dfrac{7}{18} \text { of the journey}

If i'm correct the answer is $15.97