Let

W $=(5\mathrm{.}80105$ J$)$ ln$($Vf$/$Vi$).$

Solve for the unknown quantity in each of the following cases.

$($a$)$ the final volume Vf is three times the initial volume Vi

$($b$)$ the initial volume is $1\mathrm{.}00$ m$3$ and the work W is $6\mathrm{.}05105$ J