Question 965680
When the stone is removed, occupied tank volume changes from 3/4 full to 5/8 full;
when 4500 cm^3 is removed, the tank filled volume changes from 6/8 full to 5/8 full;


When {{{4500*cm^3}}} is removed, the was a tank volume change of {{{6/8-5/8=1/8}}} of the tank's volume.


The tank volume is proportional to its height or tallness.
{{{30*30*y=4500}}}, using y for the amount of vertical length along the tank for the stone.


{{{y=4500/900}}}
{{{y=45/9}}}
{{{y=5}}}, this is centimeters.


That y=5  is  {{{(1/6)}}} of the tank's height.



Finally, if h is the actual tank height


{{{highlight_green(y/h=1/6)}}}


{{{y=h/6}}}


{{{6*y=h}}}


{{{h=6*y}}}


{{{h=6*5}}}


{{{highlight(h=30*centimeters)}}}