Question 1105123
This problem makes the assumption that after
a liquid is added to a different liquid, they 
become thoroughly mixed.
-----------------------------------------
{{{ 30 - 5 = 25 }}} liters of wine
and {{{ 5 }}} liters water
-----------------------------
{{{ 12 }}} liters of the mixture is removed
{{{ ( 25/30 )*12 = (5/6)*12 }}}
{{{ (5/6)*12 = 10 }}} liters is wine
{{{ ( 5/30 )*12 = (1/6)*12 }}}
{{{ (1/6)*12 = 2 }}} liters is water
Then {{{ 12 }}} liters of water is added
-------------------------------------
Now there is:
{{{ 10 }}} liters of wine
{{{ 12 + 2 = 14 }}} liters of water
{{{ 14/( 10 + 14 ) = 14/24 }}}
{{{ 14/24 = 7/12 }}}
7/12 of the final mixture is water
check the math