Which statement is true ? Also to what does the middle lines mean

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?

Extra points! find the missing dimension! need asap

Nicole is making carrot bread she needs 5 cups of carrots for 2 cups of sugar. what is the ratio of cups of sugar to cups of carrots that nicole will need? write the ration in three different ways