The radii of two cylinders are in the ratio 2 : 3 and their heights are in the ratio of 5 : 3. Then the ratio of their volumes is …………
The radii of two cylinders are in the ratio 2 : 3 and their heights are in the ratio of 5 : 3. Then the ratio of their volumes is …………
A) 4 : 9
B) 9 : 4
C) 20 : 27
D) 27 : 20
5 views
2 Answers
Correct option is: C) 20 : 27
Given that \(\frac {r_1}{r_2} = \frac 23 \) and \(\frac {h_1}{h_2} = \frac 53\)
\(\therefore\) \(\frac {V_1}{V_2} = \frac {\pi r^2_1 h_1}{\pi r_2^2 h_2}\) = \((\frac {r_1}{r_2})^2 (\frac {h_1}{h_2})\) = \((\frac 23)^2 \,\frac 53\)
= \(\frac {20}{27}\)
Hence, the ratio of their volumes is 20 : 27.
5 views
Answered