Question 918193
Let {{{ x }}} = ml of water to be added
{{{ .13*24 = 3.12 }}} ml of alcohol in  24% solution
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{{{ 3.12 / ( x + 24 ) = .12 }}}
{{{ 3.12 = .12*( x + 24 ) }}}
{{{ 3.12 = .12x + 2.88 }}}
{{{ .12x = 3.12 - 2.88 }}}
{{{ .12x = .24 }}}
{{{ x = 2 }}}
2 ml of water needs to be added
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check:
{{{ 3.12 / ( x + 24 ) = .12 }}}
{{{ 3.12 / ( 2 + 24 ) = .12 }}}
{{{ 3.12 / 26 = .12 }}}
{{{ 3.12 = .12*26 }}}
{{{ 3.12 = 3.12 }}}
OK