Quantitative Aptitude and Elementary Mathematics
Quantitative Aptitude and Elementary Mathematics tests school-level arithmetic with an emphasis on speed and clean calculation. The standard is not advanced mathematics; it is accurate use of fractions, ratios and formulas under time pressure.
Core syllabus
- Number system, divisibility, HCF and LCM, simplification, surds and indices.
- Percentage, ratio and proportion, average, partnership, mixture and alligation.
- Profit, loss and discount; simple and compound interest.
- Time and work, pipes and cisterns, speed–distance–time, trains and boats.
- Mensuration of 2D and 3D figures, data interpretation and basic probability.
Worked example
A can finish a job in 12 days and B in 18 days. They work together for 4 days, then A leaves. How long does B take to finish the rest? Take LCM of 12 and 18 = 36 units. A does 3 units/day, B does 2 units/day; together 5 units/day. In 4 days they finish 20 units, leaving 16. B alone finishes 16 units at 2 units/day in 8 days.
Rules worth memorising
- Simple interest = PRT/100; compound interest = P[(1 + r/100)^t − 1].
- Two-year CI rate equivalent = 2r + r²/100.
- Profit percentage is calculated on cost price; discount is calculated on marked price.
- For successive discounts, use 1 − (1 − d₁)(1 − d₂).
- A train crossing a platform covers its own length plus the platform length.
Traps that cost marks
- Computing profit on selling price when the question says cost price.
- For half-yearly compounding, halving the rate but forgetting to double the time.
- Mixing units in mensuration - centimetres with metres, or litres with cubic centimetres.
- In data interpretation, reading percentage points as percentages and ignoring the axis scale.
- Rounding too early in percentage and interest questions.
Exam approach
Convert percentages to fractions wherever possible and use the LCM unit method for work problems. Estimate the answer first, then calculate; options are often far apart.