Answer: [tex]\frac{7}{16}hour[/tex]
Step-by-step explanation:
You know that the total time was: 7/8 hour
You also know that they spent 1/2 of the time at the beach.
Therefore, to calculate the time Zach and his dog spend at the beach (which you can call x) , you must multiply both fractions (7/8 and 1/2).
Then, you obtain the following result:
[tex]x=\frac{7}{8}hour*\frac{1}{2}\\\\x=\frac{7}{16}hour[/tex]