What measurement that is equal to 20 liters

Which equation matches the graph shown ?

The volume of gas a balloon can hold varies directly as the cube of its radius. imagine a balloon with a radius of 3 inches can hold 81 cubic inches of gas. how many cubic inches of gas must be released to reduce the radius down to 2 inches?

The map shows the location of the airport and a warehouse in a city. though not displayed on the map, there is also a factory 112 miles due north of the warehouse. a truck traveled from the warehouse to the airport and then to the factory. what is the total number of miles the truck traveled?