Practicing Success
Two right circular cones of equal volumes have their heights in the ratio 4 : 9. What is the ratio of the radii of their bases, the cones coming in the same order as that in which the ratio of their heights is given? |
9 : 4 3 : 2 4 : 9 2 : 3 |
3 : 2 |
We know that, Volume of a cone = \(\frac{1}{3}\)πr2h Ratio of the heights of the cones = 4 ∶ 9. Let the radius of the two cones = m and n Also, let the heights of the cones be 4a and 9a According to the question, \(\frac{1}{3}\)π × m2 × 4a = \(\frac{1}{3}\)π × n2 × 9a = 4m2 = 9n2 = \(\frac{m}{n}\) = \(\frac{3}{2}\) Ratio of radii = 3 : 2 |