Question

A solid cone of height 9 cm with diameter of its base 18 cm is cut out from a wooden solid sphere of radius 9 cm. The percentage of wood wasted is

Answer 1

hieght of cone is 9cm
radius of cone is 9cm
therefore volume of cone will be=1/3πr²h
                                             =π3 x 9 x 9
                                             =243π
now volume of sphere is =4/3πr³
                                    =4/3π9 x 9 x 9=972π
therefore volume of wood left=972π-243π=729π
therefore percentage of wood waste=729π/972π x 100
                                                   =75% ans