From a solid cylinder whose height is 2.4 cm and diameter 1.4 cm, a conical cavity of the same height and same diameter as that of cylinder is hollowed out. Find the total surface area of the remaining solid. (Use π=227)
From a rectangular solid of metal 42 cm by 30 cm by 20 cm, a conical cavity of diameter 14 cm and depth 24 cm is drilled out. Find : (i) the surface area of remaining solid, (ii) the volume of remaining solid, (iii) the weight of the material drilled out if it weighs 7 gm per cm3.