Question 1192740
<pre>
concentration(dec.fraction)          volume            pure(as dec. fraction)
      p                                2                     2p
     .33                               6                     6*(0.33)
     .50                               8                      4
</pre>
No doubt an "easier" way can be found, but this table lets set up {{{2p+(0.33)*6=4}}}
(remember, p here is as decimal fraction instead of percent.)