Question 777294
The 600 {{{cm^3}}} is split into {{{7+5+3=15}}} parts.  
volume A is {{{(7/15)*600=280}}} {{{cm^3}}}
volume B is {{{(5/15)*600=200}}} {{{cm^3}}}
volume C is {{{(3/15)*600=120}}} {{{cm^3}}}


Instead of my working and telling you the radii of those spheres, you should find them yourself.
v for volume, {{{v=(4/3)pi*r^3}}}
{{{r^3=(3/4)v/pi}}}
{{{highlight(r=root(3,(3v)/(pi*4)))}}}