from __future__ import division
n1=1
n2=2
o=20 #in cm
r=10 #in cm
print("x=n2/i")
x=((n2-n1)/r)-(n1/o)
print("x=",x)
i=n2/x
print("The value of i in cm=",i)
from __future__ import division
n1=2
n2=1
o=15 #in cm
r=-10 #in cm
print("x=n2/i")
x=((n2-n1)/r)-(n1/o)
print("The value of i in cm= %.5f"%x)
i=n2/x
print("The value of i in cm= %d"%i)
from __future__ import division
n=1.65
r_1=40 #in cm
r_2=-40 #in cm
x=(n-1)*((1/r_1)-(1/r_2))
print("x=1/f in cm= %.4f"%x)
print("f=1/x")
f=1/x
print("f in cm= %.5f"%f)
from __future__ import division
o=9 #in cm
f=24 #in cm
x=(1/f)-(1/o)
print("x=1/i in cm= %.5f"%x)
i=1/x
print("i in cm= %.1f"%i)
print("Lateral magnification =")
m=-(i/o)
print('m= %.1f'%m)