entire area of framed pic = (20+5+5) x (10+5+5) = 600cm^2
area of frame = 600 - 20 x 10 = 400cm^2
hence the percentage = 400 / 600 = 66.67%
1) A rectangular picture ABCD measures 20cm by 10cm and is framed with a matte that is 5cm wide all around. Approximately what percentage of the entire area of the framed picture is the matte?
2) A solid cube with volume 27cm3 is constructed using 27 small 1cm3 cubes. The large cube is dipped into a can of paint. If the paint dries and the larger cube is broken apart, how many of the smaller cubes have paint on exactly two faces?