//Variable declaration
n=8.5*10**28
e=1.602*10**-19
t=2*10**-14
m=9.1*10**-31

//Calculations
Tc=n*(e**2)*t/m

//Result
printf('The mean free collision time =%0.3f *10**7 ohm**-1 m**-1  \n ',(Tc/10**7))