MATHEMATICS · Multi-part · CBSE · Mathematics · Surface Areas and Volumes · Surface Areas and Volumes
Problem
A solid metallic sphere of radius 6 cm is melted. Forty per cent of the molten metal is used to make cylindrical pens each of radius 0.5 cm and length 14 cm. The remaining metal is used to form identical solid right circular cones each of radius 2 cm and height 8 cm.
(i) Determine the number of cylindrical pens produced.
(ii) Find the number of cones obtained from the remaining metal.
(iii) Compare the total surface area of all the cones with that of the original sphere.