Which question could the expression 1000n answer? Let n = the number of gallons of gas used.
How many miles per gallon did the car get driving 1000 miles?

Let n = the number of grams of food needed for each dog.
How many grams of food are needed to feed 1000 dogs?

Let n = the number of people at the show.
How many empty seats were there at the show if there are 1000 seats at the theater?

Let n = the number of seats at the theater.
How many empty seats will there by if 1000 people come to the show?