Question

A box without a lid is to be made from cardboard. The box is 60 cm long, 40 cm wide and 50 cm high. How much cardboard (in cm²) is needed? (Ignore overlaps.)

A shopkeeper can pack sweets either in a cube-shaped box of edge 10 cm or in a cuboidal box 12 cm × 10 cm × 8 cm. Which box needs less cardboard to make, and by how much? Do both boxes hold the same amount?

A school hall is 15 m long, 10 m wide and 5 m high. Its four walls and ceiling are to be painted. There is one door of 2.5 m × 1.2 m and two windows, each 1.5 m × 1 m, which are not painted. Find the cost of painting at ₹30 per m² (answer in ₹).

A solid metal cube of edge 12 cm is melted and recast into a cuboid with a base of 18 cm × 8 cm. Find (i) the height of the cuboid, and (ii) how much more (or less) surface area the cuboid has than the cube.