//23.9
p=30//in cm
f=10//in cm
x=(1/f)-(1/p)
q=1/x

M1=-(q/p)

p=5//in cm
f=20//in cm
x=(1/f)-(1/p)
q=1/x

M2=-(q/p)


M=M1*M2
disp(M,"The magnification=")