Question

The volume of 2 spheres have a ratio of 27:125. what is the ratio of their radii

Answer 1

Using formula v of hemisphere= 2/3x22/7xr3
v of hemi a= r3= 12.8
                 = r   =2.3
v of hemi b= r3 = 59.6
                 =r    = 3.9
So the ratio is 2.3:3.9

Answer 2

The volume is scale factor³
Take the square root of the volume ratio

$\sqrt{ \frac{27}{125} }$ which is 
$\frac{ \sqrt{27} }{ \sqrt{125} }$

$\frac{3}{5}$

The ratio of their radii is 3 : 5