2. A metallic sheet is of the rectangular shape with dimensions 36 cm by 24 cm. From each corner a square of 6 cm is cut off. An open box is made from the remaining sheet. Find the volume of the box.
3. An open cuboidal box is made of wood 2.5 cm thick. Its external length, breadth and height are 60 cm, 60 cm and 50 cm respectively. Find cost of painting the inner surface at Rs 20 per 100 square cm.
