Help please help help

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?

Jim had 15 minutes to do 5 laps around his school what would his time be

The points (1, 7) and (0, 2) fall on a particular line. what is its equation in slope-intercept form?