Practice | Hashtable

Home > Practice > Arithmetic Aptitude > Area > Miscellaneous

1. The ratio of the circumferences of two circles is 2 : 3. What is the ratio of their areas ?

A. 2 : 3

B. 4 : 9

C. 9 : 4

D. None of these

Solution:

\begin{aligned} \Rightarrow \frac{2 π R_{1}}{2 π R_{2}} = \frac{2}{3} \\ \Rightarrow \frac{R_{1}}{R_{2}} = \frac{2}{3} \\ \Rightarrow \frac{π R_{1}^{2}}{π R_{2}^{2}} = {(\frac{2}{3})}^{2} \\ \Rightarrow \frac{π R_{1}^{2}}{π R_{2}^{2}} = \frac{4}{9} or 4 : 9 \end{aligned}

You must login to add comments. Login now.