Question 611186
Let {{{ x }}} = gallons of water to be added
{{{ .8*50 = 40 }}} gallons of acid in 80% solution
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{{{ 40 / ( x + 50) = .65 }}}
{{{ 40 = .65*( x + 50 ) }}}
{{{ 40 = .65x + 32.5 }}}
{{{ .65x = 7.5 }}}
{{{ x = 11.538 }}}
11.538 gallons of water must be added