UPPSC Prelims 2020 CSAT, held on Oct 11, 2020, tested candidates' reasoning, analytical, and mathematical skills. It included sections on quantitative aptitude, logical reasoning, and comprehension, aiming to assess problem-solving abilities. The CSAT paper is of qualifying nature, with candidates needing to score a minimum mark to move forward. The UPPSC selection process involves three stages: Prelims, Mains, and Interview. Those who qualify the Prelims are eligible for the Mains, and final selection is based on combined performance in the Mains and Interview stages.