Can i have some help on these 3 problems??

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?

Awindow washer cleans 42 windows in 2 hours. at this rate, how many windows did he clean in 180 minutes.

Quadrilateral ghij has coordinates g(5, 1), h(4, -3), i(6, -1), and j(2, 1). if the quadrilateral is reflected over the line y = x, what are the coordinates of h'?