posted by mary on .
A cylindrical flower pot with an open top needs to be painted. The height of the pot is 9 inches and the radius is 3 inches. If it takes Troy 5 minutes to paint 40 square inches, how long to the minute will it take him to paint the outside of the flower pot?
I came up with 20 minutes
Area of the curved surface ("outside") is
A = 2πrh
where r=3", h=9".
Check your arithmetic, I came up with a little more than 20 minutes.