text: • # question_answer The number of sphere of 6 cm diameter that can be made out of a metallic solid cylinder of diameter 4 cm and height 45 cm, is A)  5         B)  6 C)  8                                 D)  10
  
  Radius of cylinder, ${{r}_{1}}=2\,cm$ And height of cylinder, ${{h}_{1}}=45\,cm$ $\therefore$ Volume of cylinder $=\pi {{2}^{2}}\times 45$                                  $=180\pi$ Now, radius of sphere $=3\,cm$ $\therefore$ Volume of sphere $=\frac{4}{3}\pi {{(3)}^{3}}$                                $=36\pi$ $\therefore$ Number of required sphere $=\frac{180\pi }{36\pi }=5$