Question 957863
Let {{{ x }}} = litres of water to be added
{{{ .25*6000 = 1500 }}} = litres of salt in 25% mixture
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{{{ 1500 / ( x + 6000 ) = .23 }}}
{{{ 1500 = .23*( x + 6000 ) }}}
{{{ 1500 = .23x + 1380 }}}
{{{ .23x = 120 }}}
{{{ x = 521.74 }}}
521.74 litres of water are needed
check:
{{{ 1500 / ( 521.74 + 6000 ) = .23 }}}
{{{ 1500 / 6521.74 = .23 }}}
{{{ 1500 = .23*6521.74 }}}
{{{ 1500 = 1500.0002 }}}
close enough