NinetynineInteger equations solved by listing factor pairs
CAT has tested this idea 5 times across 5 papers, from 2017 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 Q22 | n^2 − m^2 = 105 | 4 |
| CAT 2017 Slot 2 · QA Q28 | 1/a + 1/b = 1/9 becomes (a−9)(b−9) = 81 | 3 |
| CAT 2025 Slot 2 · QA Q1 | (m+2n)(2m+n) = 27; maximise 2m − 3n | 17 |
| CAT 2022 Slot 1 · QA Q4 | y(x+z) = 19 and z(x+y) = 51; minimise xyz | 34 |
| CAT 2020 Slot 1 · QA Q20 | ab = 432, bc = 96, c < 9; minimise sum | C |
Part of Number Systems (40 questions since 2017).