First you have to find the area of the hexagon and you multiply it by two because there is two of them then you find the area of the rectangle and you multiply it by six because there six of them. After you have to find the area of a cylinder which is made of two circles and one rectangle. You then multiply the area of the hexagons and rectangles by .01 and multiply the area of the cylinder by .02. Finally to find the 20% you multiply 15 and .2 then add 15 and add the cost of the materials and the cost of the box to that total and that's how you get $24.