Question

Martin uses 5/8 of a gallon of paint to cover4/5 of a wall. What is the unit rate at which Martin paints in walls per gallon

Answer 1

Since your answer needs to be in walls per gallon I would assume you divide 4/5 by 5/8 since that would tell you how many walls he can paint in an hour.
4/5 walls÷5/8 gallons=1.28walls/gallon.

I hope this helps.  Let me know if anything is unclear.

Answer 2

Answer:

Unit rate at which Martin paints in walls per gallon is $\frac{32}{25} wall/gallon$.

Explanation:

Rate is defined as ratio between two quantities with different units.

Gallons of paint used by Martin = $\frac{5}{8}$ gallons

Portion of wall Martin wishes to pint = $\frac{4}{5}$ wall

Rate at which Martin paints the wall:

$Rate=\frac{\text{Portion of wall covered}}{\text{Paint used}}$

$Rate=\frac{\frac{4}{5} wall}{\frac{5}{8} gallon}=\frac{32}{25} wall/gallon$

Unit rate at which Martin paints in walls per gallon is $\frac{32}{25} wall/gallon$.