Question 1107030
You didn't add any salt to the beaker,
so the 2% salt is still {{{ .01*10 = .1 }}} kg
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Let {{{ x }}} = the total kg of the final mixture
{{{ .1 / x = .02 }}}
{{{ x = .1/.02 }}}
{{{ x = 5 }}}
{{{ x - .1 = 5 - .1 }}}
{{{ 5 - .1 = 4.9 }}}
There is .1 kg of salt and 
4.9 kg of water in the beaker after evaporation
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There is 5 kg of salt water at this time
check the math