Question 1006572
Fill rate both parts open is  {{{1/6-1/9}}}
{{{(3-2)/18}}}
{{{1/18}}} TUB per MINUTE, which means 18 minutes to fill the tub this way.


RT=V, and units of volume V is in TUBs.  Uniform rate rule for flow rates.


Volume used for filling just from inlet pipe,
{{{(1/6)*18=3*tubs}}}


Volume which went out while filling, because drain was open,
{{{(1/9)18=2*tubs}}}


{{{3-2=1*tubs}}}
Amount of water lost was 2 tubs-worth.