Please answer step by step and clearly to obtain the given answers. I really need to learn this perfectly.

3) Consider free-radical monochlorination of 3-methylpentane. Draw all the unique products and predict the percent composition of the products. The relative reactivity of H abstraction in a chlorination reaction is 1:2:3=1:3.5:5. Answers: 20%,53.33%,16.67%,10%