Question 633327
Let {{{ x }}} = gallons of water needed
{{{ 20 / ( x + 20 ) = .03 }}}
{{{ 20 = .03*( x + 20 ) }}}
{{{ 20 = .03x + .6 }}}
{{{ .03x = 19.4 }}}
{{{ x = 646.667 }}} gallons of water