Answer
(a) $73.8cm$
(b) $42.0$
Work Step by Step
(a) We can find the distance between the objects as
$L=f_{objective}+f_{eyepiece}$
We plug in the known values to obtain:
$L=75.6+(-1.8)=73.8cm$
(b) The angular magnification can be determined as follows:
$M_{total}=-\frac{f_{objective}}{f_{eyepiece}}$
We plug in the known values to obtain:
$M_{total}=-\frac{75.6}{-1.80}=42.0$
