Answer
a) $d_o=0.85cm$
b) $M=210X$
Work Step by Step
a) $d_i=l-f_e=14.8cm-1.8cm=13.0cm$
$\frac{1}{f}=\frac{1}{d_i}+\frac{1}{d_o}$
$d_o=\frac{f_od_i}{d_i-f_o}=\frac{0.80cm\times13.0cm}{13.0cm-0.80cm}=0.852cm$
b) $M=\frac{N}{f_e}\bigg(\frac{l-f_e}{d_o}\bigg)=\frac{25.0cm}{1.8}\bigg(\frac{14.8-1.8}{0.852cm}\bigg)=210X$
