Multiple choice please answer please

The graph shows the rate at which paint is used to paint a wall.enter values to complete each statement below based on the graph.when 1 gallon of paint has been used, ( # ) square feet of the wall will be painted.the unit rate is ( # )square feet per gallon.

On a piece of paper graph f(x)=5•(0.4)^x

If set d is not the empty set but is a subset of set e, then which of the following is true? d ∩ e = d d ∩ e = e d ∩ e = ∅