Originally Posted by
chisigma ... if the base is $\displaystyle 10$ , then is $\displaystyle \log 5 = \log 10 - \log 2 = 1 - \log 2$ ... but more simple is $\displaystyle \log 20 = 1 + \log 2$ and $\displaystyle \log 30 = 1 + \log 3$ ...
Kind regards
$\displaystyle \chi$ $\displaystyle \sigma$