Question 1099371
<pre>
PIPE          RATE in TUB per MINUTES

hot tap        {{{1/9}}}
cold tap       {{{1/6}}}
drain         {{{-1/4}}}
</pre>




x, unknown time to finish filling tub while all three pipes were open
{{{(1/9)*3+(1/9+1/6)*1+(1/9+1/6-1/4)*x=1}}}

-

{{{1/3+1/9+1/6+(1/9+1/6-1/4)x=1}}}

{{{LCD=36}}};

{{{12+4+6+(4+6-9)x=36}}}

{{{22+x=36}}}

{{{x=36-22}}}

{{{highlight(x=14)}}}
fourteen minutes