A ferry traveled \dfrac16
6
1
​ start fraction, 1, divided by, 6, end fraction of the distance between two ports in \dfrac37
7
3
​ start fraction, 3, divided by, 7, end fraction hour. The ferry travels at a constant rate.

Answer:

Ferry rate = [tex]\frac{7}{18}[/tex] miles/hour

Solution:

Ferry travelled [tex]\frac{1}{6}[/tex] miles of distance between two ports in [tex]\frac{3}{7}[/tex] hours  

Rate of Ferry is equal to distance travelled over time taken.  

Rate of ferry = [tex]\frac{\frac{1}{6}}{\frac{3}{7}}[/tex]

Now we calculate it.  

Rate of ferry =[tex]\frac{1}{6}\div \frac{3}{7}[/tex] miles/hour  

Rate of ferry = [tex]\frac{7}{18}[/tex] miles/hour