• # question_answer Two circular cylinders of equal volume have their heights in the ratio 9 : 16 Find the ratio of their radii A)  4 : 3       B)  5 : 6           C)  2 : 5                            D)  5 : 7

(a): Let height be $9x$ and $16x$ Radii be ${{y}_{1}}$and ${{y}_{2}}$ Since vol. is same, $\pi {{y}_{1}}^{2}.9x=\pi {{y}_{2}}^{2}.16x$ $\Rightarrow {{\left( \frac{{{y}_{1}}}{{{y}_{2}}} \right)}^{2}}=\frac{16}{9}\Rightarrow \frac{{{y}_{1}}}{{{y}_{2}}}=4/3=4:3$.