Master placement exams with our comprehensive collection of quantitative aptitude formulas. Essential formulas, shortcuts, and examples for TCS, Infosys, Wipro, and all major campus placements.
| Formula | Explanation |
|---|---|
| Percentage = (Part/Whole) × 100 | Basic percentage calculation |
| x% of y = (x/100) × y = y% of x | Percentage is commutative |
| % Increase = [(New - Old)/Old] × 100 | Calculate percentage increase |
| % Decrease = [(Old - New)/Old] × 100 | Calculate percentage decrease |
| Net % Change = a + b + (ab/100) | Successive change of a% then b% |
Q: A salary increased by 20% and then decreased by 20%. What is the net change?
A: Net change = 20 + (-20) + (20 × -20)/100 = 0 - 4 = -4% decrease
| Formula | Usage |
|---|---|
| Profit = SP - CP | When SP > CP |
| Loss = CP - SP | When CP > SP |
| Profit % = (Profit/CP) × 100 | Profit percentage on cost |
| Loss % = (Loss/CP) × 100 | Loss percentage on cost |
| SP = CP × (100 + Profit%)/100 | Find SP from CP and profit % |
| SP = CP × (100 - Loss%)/100 | Find SP from CP and loss % |
| CP = SP × 100/(100 + Profit%) | Find CP from SP and profit % |
| Discount = MP - SP | MP = Marked Price |
| Concept | Formula |
|---|---|
| Ratio | a:b = a/b |
| Proportion | a:b = c:d → a×d = b×c (cross multiply) |
| Componendo | If a/b = c/d then (a+b)/b = (c+d)/d |
| Dividendo | If a/b = c/d then (a-b)/b = (c-d)/d |
| Componendo-Dividendo | If a/b = c/d then (a+b)/(a-b) = (c+d)/(c-d) |
| Mean Proportion | If a:b = b:c then b = √(a×c) |
Q: If A:B = 2:3 and B:C = 4:5, find A:B:C
A: Make B common: A:B = 8:12, B:C = 12:15 → A:B:C = 8:12:15
| Formula | Application |
|---|---|
| Work = Rate × Time | Basic work formula |
| Rate = 1/Time (to complete 1 unit) | Efficiency per unit time |
| Time = Work/Rate | Time to complete work |
| Combined Rate = 1/A + 1/B | A and B working together |
| Time Together = (A×B)/(A+B) | If A finishes in 'a' days, B in 'b' days |
| M₁D₁H₁/W₁ = M₂D₂H₂/W₂ | M=Men, D=Days, H=Hours, W=Work |
Q: A finishes in 10 days, B in 15 days. Together?
A: (10×15)/(10+15) = 150/25 = 6 days
| Formula | Description |
|---|---|
| Distance = Speed × Time | Basic formula (D = S × T) |
| Speed = Distance/Time | Finding speed |
| Time = Distance/Speed | Finding time |
| Avg Speed = Total Distance/Total Time | For varying speeds |
| Avg Speed = 2ab/(a+b) | Same distance at speeds a and b |
| Relative Speed = (a+b) | Objects moving towards each other |
| Relative Speed = |a-b| | Objects moving same direction |
SI = (P × R × T)/100
Amount = P + SI = P(1 + RT/100)
Amount = P(1 + R/100)ⁿ
CI = Amount - P
Difference between CI and SI for 2 years:
CI - SI = P(R/100)² = PR²/10000
Rectangle
Area = l × b | Perimeter = 2(l + b)
Square
Area = a² | Perimeter = 4a | Diagonal = a√2
Circle
Area = πr² | Circumference = 2πr
Triangle
Area = ½ × base × height
Trapezium
Area = ½ × (a + b) × h
Cube
Volume = a³ | Surface = 6a²
Cuboid
Volume = l×b×h | Surface = 2(lb+bh+hl)
Cylinder
Volume = πr²h | CSA = 2πrh
Cone
Volume = (1/3)πr²h | CSA = πrl
Sphere
Volume = (4/3)πr³ | Surface = 4πr²
Percentage, Profit & Loss, Time & Work, and Speed-Distance-Time form the core of most aptitude tests. Master these first, then move to other topics. These topics typically account for 60-70% of questions.
First, identify the topic and relevant formula. Then, check if any shortcuts apply. Practice mental math for simple calculations. Time yourself to improve speed. Always verify your answer if time permits.
Most placement exams (TCS, Infosys, Wipro) have 15-25 quantitative aptitude questions. Time limit is usually 1-2 minutes per question. Focus on accuracy first, then improve speed.
Yes, but with understanding. Memorize the basic formulas, but understand when to apply each. Practice enough problems that formulas become second nature. Don't just memorize—know why each formula works.
Practice mental math daily. Learn tables up to 20, squares up to 30, and cubes up to 15. Master percentage-to-fraction conversions. Use approximation techniques for complex calculations.
Dedicate 1-2 hours daily for 2-3 months before placements. Solve at least 10-15 problems per topic. Take weekly mock tests to track progress and identify weak areas.
Knowing formulas is just the first step. Practice with our free aptitude test tool to apply these formulas and improve your speed.
