Question 1128477
Let {{{ x }}} = ounces of 5% solution needed
{{{ .1*18 = 1.8 }}} ounces of alcohol in 10% solution
{{{ ( .05x + 1.8 ) / ( x + 18 ) = .06 }}}
{{{ .05x + 1.8 = .06*( x + 18 ) }}}
{{{ .05x + 1.8 = .06x + 1.08 }}}
{{{ .01x = .72 }}}
{{{ x = 72 }}}
72 ounces of 5% solution are needed
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check:
{{{ ( .05*72 + 1.8 ) / ( 72 + 18 ) = .06 }}}
{{{ ( 3.6 + 1.8 ) / 90 = .06 }}}
{{{ 5.4 = 5.4 }}}
OK