Question 585730
Let {{{ w }}} = liters of water needed
given:
{{{ .05*20 = 1 }}} liter of salt in 5% solution
{{{ 1 / ( 20 + w ) = .01 }}}
{{{ 1 = .01*( 20 + w ) }}}
{{{ 1 = .2 + .01w }}}
{{{ .01w = 1 - .2 }}}
{{{ .01w = .8 }}}
{{{ w = .8/.01 }}}
{{{ w = 80 }}}
80 liters of water are needed
check:
{{{ 1 / ( 20 + w ) = .01 }}}
{{{ 1 / ( 20 + 80 ) = .01 }}}
{{{ 1 / 100 = .01 }}}
OK