Quantitative Aptitude: Formulas, Shortcuts and Solved Questions
Quantitative aptitude is the maths section of placement tests. It rewards clear formulas and quick arithmetic more than advanced theory. Use the table below as a revision sheet, then solve the examples.
Key formulas
| Topic | Formula |
|---|---|
| Percentage change | (Change ÷ Original) × 100 |
| Profit % | (Profit ÷ Cost price) × 100 |
| Time and work | Together = (A × B) ÷ (A + B) days |
| Speed, distance, time | Distance = Speed × Time |
| km/h to m/s | Multiply by 5/18 |
| Average | Sum ÷ Number of items |
Shortcut tricks
For time and work, convert days into units of work per day. For percentages, remember that 12.5% = 1/8, 16.67% = 1/6 and 33.33% = 1/3. These fractions often replace long calculations.
5 solved examples
1. A price rises from ₹80 to ₹100. What is the percentage increase?
Change = 20. 20 ÷ 80 × 100 = 25%.
2. A can finish a job in 12 days and B in 24 days. How long do they take together?
(12 × 24) ÷ (12 + 24) = 288 ÷ 36 = 8 days.
3. An item bought for ₹500 is sold for ₹600. Find the profit percentage.
Profit = 100. 100 ÷ 500 × 100 = 20%.
4. Divide ₹600 in the ratio 2 : 3.
Total parts = 5, so one part = 120. Shares = ₹240 and ₹360.
5. Convert 60 km/h into m/s.
60 × 5/18 = 16.67 m/s (about 50/3).
Keep practising
Mix these topics with general aptitude questions and answers and the chapter-wise practice guide.
Frequently asked questions
What topics come under quantitative aptitude?
Percentages, profit and loss, ratio, averages, time and work, time speed and distance, simple and compound interest, number systems, and permutations and combinations.
Is quantitative aptitude difficult for engineering students?
The maths is mostly school level. The challenge is speed, so timed daily practice matters more than learning advanced methods.