previous year question papers are really important while preparing for any entrance exam. You can find theSSC CHSL Question Papers here.
If you really want to beat the average, make sure to keep the following things in mind:
Attempt after completing syllabus: Ideally, Previous papers should be attempted after completing the syllabus, in full exam like setting under time considerations.
Accuracy, Time and Speed are the key factors that decide the final scores in the actual setting. Previous papers should be attempted with a similar mindset.
Summary of Formulas and Concepts: While attempting the previous year papers, aspirants can maintain a thick notebook with all the formulas and keep updating it with every sectional test they give and revise it once every few days.