Answer
$66cm, 17cm$
Work Step by Step
(a) We can find the image distance as
$d_i=-md_{\circ}$
We plug in the known values to obtain:
$d_i=-(-3)(22)=66cm$
(b) We can find the focal length as
$f=(\frac{1}{d_{\circ}}+\frac{1}{d_i})^{-1}$
We plug in the known values to obtain:
$f=(\frac{1}{22}+\frac{1}{66})^{-1}$
$f=17cm$