Question 528169
Let {{{ w }}} = ml of water needed
given:
{{{ .25*50 = 12.5 }}} ml of acid in 25% solution
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{{{ 12.5 / ( 50 + w) = .1 }}}
{{{ 12.5 = .1*( 50 + w ) }}}
{{{ 12.5 = 5 + .1w }}}
{{{ .1w = 12.5 - 5 }}}
{{{ w = 7.5 / .1 }}}
{{{ w = 75 }}}
75 ml of water is needed