8th Class Mathematics Mensuration Question Bank Mensuration

  • question_answer
    The radii of the bases of two cylinders are in the ratio of 1 : 2 respectively and their heights are in the ratio 2 : 1 respectively. Find the ratio of their volumes.

    A)  1 : 2   

    B)         1 : 4

    C)  2 : 1   

    D)         4 : 1   

    Correct Answer: A

    Solution :

    Given that, \[\frac{{{r}_{1}}}{{{r}_{2}}}=\frac{1}{2}\] and \[\frac{{{h}_{1}}}{{{h}_{2}}}=\frac{2}{1}\] \[\therefore \frac{{{V}_{1}}}{{{V}_{2}}}=\frac{\pi r_{1}^{2}{{h}_{1}}}{\pi r_{2}^{2}{{h}_{2}}}=\left( \frac{{{r}_{1}}}{{{r}_{2}}} \right)\times \left( \frac{{{h}_{1}}}{{{h}_{2}}} \right)\] \[={{\left( \frac{1}{2} \right)}^{2}}\times \left( \frac{2}{1} \right)=\frac{1}{4}\times \frac{2}{1}=\frac{1}{2}\] \[\Rightarrow {{V}_{1}}:{{V}_{2}}=1:2\]


You need to login to perform this action.
You will be redirected in 3 sec spinner