Answer
The product ratio of 1-chloropropane to 2-chloropropane would be $3:1$
Work Step by Step
In propane, there are 6 primary hydrogens and 2 secondary hydrogens, there ratio is $3:1$. Assuming that the secondary and primary hydrogens get substituted by chlorine at the same rate, the products formed would be in the ratio of the hydrogens, i.e, the product ratio of 1-chloropropane to 2-chloropropane would be $3:1$.
