1. Three copper cubes whose edges measure 5 cm, 4 cm and 3 cm respectively are melted to forma single cube. Find the surface area of the new cube. 2. A cylindrical tube opened at both the ends is made of iron sheet which is 2 cm thick. If the outer diameter is 16 cm and its length is 100 cm, find how many cubic centimeters of iron has been used in making the cube.? 3. A shop keeper has one spherical laddu of radius 5 cm. With the same amount of material, howmany laddus of radius 2.5 cm can be made? 4. Find the slant height and curved surface area of a cone whose volume is 12935 cu. cm and the diameter of the base is 42 cm. 5. A right triangle with sides 6 cm, 8 cm and 10 cm is revolved about the side 8 cm. Find the volume and surface area of the solid so formed.