To find the unit rate of 7/8 square foot in 1/4 hour, we can proceed as follows:
[tex]\frac{\frac{7}{8}}{\frac{1}{4}}=\frac{7}{8}\cdot4=\frac{28}{8}=\frac{14}{4}=\frac{7}{2}=3.5[/tex]The unit rate is, therefore, 3.5 square foot an hour or
3.5 ft^2/hour.