Two cones have their heights in the ratio 1 : 2 and the diameters of t...
If the ratio of their diameters = 2 : 1, then the ratio of their radii will also be = 2 : 1
Let the radii of the broader cone = 2 and height be = 1
Then the radii of the smaller cone = 1 and height be = 2
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Two cones have their heights in the ratio 1 : 2 and the diameters of t...
Given information:
- Heights of two cones are in the ratio of 1:2
- Diameters of their bases are in the ratio of 2:1
To find:
Ratio of their volumes
Solution:
Let the height of the first cone be h1 and the height of the second cone be h2.
Let the diameter of the base of the first cone be d1 and the diameter of the base of the second cone be d2.
Let the radius of the base of the first cone be r1 and the radius of the base of the second cone be r2.
From the given information, we know that:
h1 : h2 = 1 : 2
d1 : d2 = 2 : 1
We also know that the volume of a cone is given by:
V = (1/3)πr^2h
where r is the radius of the base and h is the height of the cone.
We can use the information about the diameters of the bases to find the ratio of the radii:
r1 = (d1/2) and r2 = (d2/2)
r1 : r2 = (d1/2) : (d2/2) = d1 : d2 = 2 : 1
Now, we can use the information about the heights to find the ratio of the volumes:
V1/V2 = (1/3)πr1^2h1 / (1/3)πr2^2h2
V1/V2 = r1^2h1 / r2^2h2
V1/V2 = [(d1/2)^2h1] / [(d2/2)^2h2]
V1/V2 = (d1^2/4)(h1/h2)(1/d2^2)
Substituting the given ratios:
V1/V2 = (2^2/4)(1/2)(1/1^2)
V1/V2 = 1/2
Therefore, the ratio of the volumes of the two cones is 2:1. Hence, option B is the correct answer.
Two cones have their heights in the ratio 1 : 2 and the diameters of t...
2:1