NinetynineCount divisors of a special form using prime-factor exponents
CAT has tested this idea 5 times across 5 papers, from 2019 to 2025. Solve one, and the others are the same method with different numbers or wording, which is why repeated concepts are the most efficient thing to practise.
| Question | What it asks | Answer |
|---|---|---|
| CAT 2019 Slot 2 · QA Q6 | perfect-square factors greater than 1 | 44 |
| CAT 2025 Slot 2 · QA Q11 | divisors of the form 3r + 1 | A |
| CAT 2023 Slot 3 · QA Q6 | first two numbers with exactly 15 factors | 468 |
| CAT 2023 Slot 2 · QA Q6 | numbers below 50 with exactly four factors | 15 |
| CAT 2020 Slot 3 · QA Q26 | pairs a ≤ b with ab = 4^2017 | B |
Part of Number Systems (40 questions since 2017).