Question 616424
{{{ .07*30 = 2.1 }}} ml
{{{ .02*30 = .6 }}}  ml
The concentration is:
{{{ ( 2.1 + .6 ) / ( 30 + 30 ) = 2.7 / 60 }}}
{{{ 2.7/60 = .045 }}}
{{{ .045*100 = 4.5 }}}
The concentration is 4.5%