Question 690824
How much salt is in the original solution?
{{{ .52*7 = 3.64 }}} liters
Let {{{ w }}} = liters of water that was evaporated
{{{ 3.64 / ( 7 - w ) = .91 }}}
{{{ 3.64 = .91*( 7 - w ) }}}
{{{ 3.64 = 6.37 - .91w }}}
{{{ .91w = 6.37 - 3.64 }}}
{{{ .91w = 2.73 }}}
{{{ w = 2.73 / .91 }}}
{{{ w = 3 }}}
3 liters of water must be evaporated
check:
{{{ 3.64 / ( 7 - w ) = .91 }}}
{{{ 3.64 / ( 7 - 3 ) = .91 }}}
{{{ 3.64 / 4 = .91 }}}
{{{ 3.64 = .91*4 }}}
{{{ 3.64 = 3.64 }}}
OK