Question 786193
Let {{{ x }}} = ml of reagent
{{{ x / ( 77 + x ) = .3 }}}
{{{ x = .3*( 77 + x ) }}}
{{{ x = 23.1 + .3x }}}
{{{ .7x = 23.1 }}}
{{{ x = 33 }}}
33 ml of reagent are needed