log(8)6

You will need a calculator to solve this one i believe. So the way to do it is as follows. The log button on the calculator is actually Log(10). So you do Log(10)6 / Log(10)8 = Answer. This turns out to be =0.8616541669. Hope this helps. I know it is not much of an explanation.

-G

$\log_86\approx0.861654166907$