The volume of a frustum of a cone is given by $V=\large\frac{1}{3} $$ \pi h \{ r_1^2+r_1r_2+r_2^2\}$ Where $'V' $ is the volume , $'h'$ is the height of the frustum $r_1$ and $r_2$ are respectively the upper and lower radii of the frustum of cone. which of the following gives $h$ in terms of $v, r$ and $r_2$?

Question

$\begin{array}{1 1} (a)\;h= \large\frac{3V}{\pi h} \{r_1^2+r_1r_2+r_2^2\} \\ (b)\;h= \large\frac{\pi h}{3V} \{r_1^2+r_1r_2+r_2^2\} \\(c)\;h= \large\frac{3V}{\pi h \{r_1^2+r_1r_2+r_2^2\}} \\(d)\;h= \large\frac{V}{\pi h} \{r_1^2+r_1r_2+r_2^2\} \end{array} $