The role of Quantitative Aptitude in Tier I
Quantitative Aptitude is one of four sections in CGL Tier I: 25 questions, 50 marks, a separate 15-minute timer, +2 for a correct answer and −0.50 for a wrong one. It is usually the section that uses the whole 15 minutes, because the others are more recall-based. The mathematics is school-level; the difficulty is speed. A candidate who solves a percentage problem in 40 seconds by recognising a shortcut gains minutes that another candidate loses on the same problem done the long way. Because the timer is sectional, minutes saved here cannot be spent on other sections, so the aim is to finish all 25 questions with accuracy inside the 15 minutes, or to know which to leave.
Topic map
| Area | Topics | Nature of questions |
|---|---|---|
| Arithmetic | Percentage, profit and loss, discount, simple and compound interest, ratio and proportion, averages, ages, mixtures, time and work, time-speed-distance, partnership | Largest share; direct formula or shortcut questions |
| Number system and simplification | HCF and LCM, divisibility, remainders, simplification, squares and roots | Quick questions if basics are memorised |
| Algebra | Linear and quadratic equations, identities, inequalities | Identity-based; short |
| Geometry | Triangles, circles, quadrilaterals, similarity, angles | Standard results; diagram-based |
| Mensuration | Areas, perimeters, volumes, surface areas | Formula-based |
| Trigonometry and heights and distances | Identities, ratios, simple applications | Formula and angle-table based |
| Data interpretation | Tables, bar charts, line graphs, pie charts | Reading plus percentage and ratio |
Check the syllabus in the SSC notice for your year; the weight of each topic varies.
What the questions look like
Compound interest. What is the compound interest on 8,000 at 5% per annum for 2 years? The amount is 8,000 × 1.05 × 1.05 = 8,820, so the interest is 820.
Time and work. A can finish a job in 12 days and B in 18 days. Working together, how long will they take? Combined rate = 1/12 + 1/18 = 5/36, so 36 ÷ 5 = 7.2 days.
Profit and loss. An article bought for 400 is sold for 500. What is the profit percentage? 100 ÷ 400 = 25%.
Algebra. If a + b = 7 and ab = 10, find a² + b². a² + b² = (a + b)² − 2ab = 49 − 20 = 29.
Geometry. The angles of a triangle are in the ratio 3 : 4 : 5. What is the largest angle? The sum is 180°, so each part is 15° and the largest angle is 5 × 15° = 75°.
Mensuration. Find the area of a circle of radius 14 cm (π = 22/7). (22/7) × 14 × 14 = 616 sq cm.
Each takes 20 to 40 seconds with the right method. That is the benchmark to practise against.
Speed methods worth learning
- Fractions for percentages: 12.5% is 1/8, 16.67% is 1/6, 33.33% is 1/3, 37.5% is 3/8. They make percentage calculations mental.
- Multiplying factors: for successive changes, multiply factors (a 20% rise then a 20% fall gives 1.2 × 0.8 = 0.96, a 4% net fall).
- Work as units: take the LCM of the days as the total work.
- Identities: remember (a + b)², (a − b)² and a³ + b³ forms.
- Squares and cubes: learn squares to 30 and cubes to 15; see squares, cubes and roots practice.
- Approximation: round and compare with the options in data interpretation.
More methods are collected in mental maths techniques. Learn each method with its reason, so you do not misapply it.
Time management for 15 minutes
| Stage | Time | What to do |
|---|---|---|
| First pass | About 11 minutes | Solve questions where the method is clear in 5 seconds; mark others |
| Second pass | About 3 minutes | Return to the marked questions that look reachable |
| Last minute | About 1 minute | Check that doubtful answers are set; do not change answers without reason |
If a question needs more than about 60 seconds, mark it. A 15-minute section does not allow lengthy work, and the best candidates leave two or three questions without regret. See how to pick which questions to skip.
Negative marking in Quantitative Aptitude
With +2 and −0.50, the break-even accuracy is 20%. After eliminating one option, a guess has a clearly positive expected value; with no elimination it is slightly positive but small. Because time is the scarcer resource, the usual mistake is not too few guesses but spending 90 seconds on a question you will answer wrongly. Track net marks from guessed answers across mocks. See our negative marking guide.
How to practise
- Topic sets (10 to 15 questions): daily in the early phase, at 30 to 40 seconds per question.
- Calculation drills: ten minutes a day on squares, fractions and simplification.
- 15-minute sectionals: two or three a week in the middle phase.
- Full papers: weekly in the last two months, to see how Quant behaves in the sequence.
Our topic pages cover the main drills: percentage, profit and loss, simple interest, compound interest, time and work, time, speed and distance, mensuration and data interpretation.
Analysing your Quant result
| Pattern | Probable cause | Action |
|---|---|---|
| Cannot finish 25 questions | Slow methods or no skip rule | Learn shortcuts; cap at 60 seconds |
| Wrong answers with correct method | Arithmetic slips | Estimation; check the last step |
| Errors in one topic | Concept gap | Topic repair: 15 questions within a week |
| Many guesses wrong | Guessing without elimination | Compute net marks by tag; adjust |
| Accuracy falls late in the section | Hurrying | Practise the 11-3-1 split |
Common mistakes in Quant preparation
- Learning shortcuts without understanding why they work.
- Practising untimed for months.
- Neglecting data interpretation, which supplies several questions.
- Not memorising squares, cubes and fractions.
- Reviewing only wrong answers, not slow correct ones.
Related pages
See the SSC CGL hub, the exam pattern and the mock test strategy. Other sections: Reasoning, English and General Awareness. For a worked review, read how to use mock tests for SSC CGL. Quant tests published by institutes appear below.
Note: the section structure above reflects the Tier I scheme published on ssc.gov.in; confirm the current pattern in the notice for your year.