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In what ratio are the volumes of a cylinder, a cone and a sphere, if each has the same diameter and the same height?

Solution

✅ Correct Option: 3

All three shapes have the same diameter dd and the same height hh.

This means radius r=d2r = \frac{d}{2} for all three shapes.

For a sphere, the height equals its diameter (the distance from top to bottom).

Therefore: h=d=2rh = d = 2r


The volume formulas are:

Cylinder: V=πr2hV = \pi r^2 h

Cone: V=13πr2hV = \frac{1}{3}\pi r^2 h

Sphere: V=43πr3V = \frac{4}{3}\pi r^3


Substituting h=2rh = 2r into each formula:

Cylinder:

V1=πr2hV_1 = \pi r^2 h

V1=πr2(2r)V_1 = \pi r^2(2r)

V1=2πr3V_1 = 2\pi r^3

Cone:

V2=13πr2hV_2 = \frac{1}{3}\pi r^2 h

V2=13πr2(2r)V_2 = \frac{1}{3}\pi r^2(2r)

V2=2πr33V_2 = \frac{2\pi r^3}{3}

Sphere:

V3=43πr3V_3 = \frac{4}{3}\pi r^3


The ratio is:

Cylinder : Cone : Sphere =2πr3:2πr33:4πr33= 2\pi r^3 : \frac{2\pi r^3}{3} : \frac{4\pi r^3}{3}

Removing the common factor πr3\pi r^3:

=2:23:43= 2 : \frac{2}{3} : \frac{4}{3}

Multiplying by 3:

=6:2:4= 6 : 2 : 4

Dividing by 2:

=3:1:2= 3 : 1 : 2

Therefore, the volume ratio is 3:1:23 : 1 : 2.

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