Calculating molar conductance of CaCl2 Ok, so the following question is given in my text book. 


  Of the molar conductance value of $\ce{Ca^2+}$ and $\ce{Cl^-}$ at infinite dilution are respectively $118.88\times10^{-4}$ and $77.33\times10^{-4}$ then that of $\ce{CaCl2}$ is  (all have same unit)


So what I did was I added the molar conductivity of $\ce{Ca^2+}$ and added $2\times$ molar conductivity of  $\ce{Cl^-}$. I got the answer. It was one of the options. So I basically wanted to know: Did I do it correctly and is my process correct? And if I did it wrong then what is the correct process?
Yes, the process is correct, but do you understand why?