All 152 Number System & Series Previous Year Questions for UPSC CSAT, with answers and explanations. Click any question for the full solution.
Across 2014–2025, UPSC CSAT has asked 152 Number System & Series questions — an average of 12.7 per year. The heaviest year was 2025 with 23 questions; the lightest was 2014 with 5. Use the year-wise split below to see where the paper has been concentrating.
| Year | Questions | Share |
|---|---|---|
| 2025 | 23 | 15% |
| 2024 | 16 | 11% |
| 2023 | 21 | 14% |
| 2022 | 18 | 12% |
| 2021 | 14 | 9% |
| 2020 | 19 | 13% |
| 2019 | 10 | 7% |
| 2018 | 6 | 4% |
| 2017 | 9 | 6% |
| 2016 | 5 | 3% |
| 2015 | 6 | 4% |
| 2014 | 5 | 3% |
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