Question : The ratio of the volume of two cylinders is 13 : 1 and the ratio of their heights is 13 : 9. If the area of the base of the second cylinder is 154 cm2, then what will be the radius of the first cylinder?
Option 1: 42 cm
Option 2: 21 cm
Option 3: 28 cm
Option 4: 14 cm
Correct Answer: 21 cm
Solution :
Volume of a cylinder =
It is given that the ratio of the volume of two cylinders is
and ratio of heights is
⇒
⇒
⇒
⇒
⇒
Hence, the correct answer is 21 cm.