Question 312097
Total length is 8 cm.
1.{{{x+y=8}}}
The volume of the cylinder is 
{{{Vcyl=pi*R^2*x}}}
The volume of a cone is,
{{{Vcone=(pi/3)*R^2*y}}}
The total crayon volume is. 
{{{Vtotal=Vcyl+Vcone=5}}}
{{{Vtotal=pi*R^2*x+(pi/3)*R^2*y=5}}}
{{{R=D/2=1/2}}}
{{{R^2=1/4}}}
{{{(pi/4)*x+(pi/12)y=5}}}
Multiply by {{{(12/pi)}}},
2.{{{3x+y=60/pi}}}
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.
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Subtract eq. 1 from eq. 2,
{{{x+y-3x-y=8-60/pi}}}
{{{-2x=8-60/pi}}}
{{{highlight_green(x=30/pi-4)}}}
Then from eq. 1,
{{{x+y=8}}}
{{{y=8-x=8-30/pi+4}}}
{{{highlight_green( y=12-30/pi)}}}