General Aptitude

Percentages Tutorial

Master percentages for placement exams. These patterns cover most frequently asked question types. Practice each pattern until you can solve in under 20 seconds.

Start Quiz All Categories

Key Formulas

Percent = (Value / Total) × 100
New Value = Old × (100 ± Percent) / 100
Discount = Marked Price - Selling Price
Profit = SP - CP | Profit % = (Profit / CP) × 100
Loss = CP - SP | Loss % = (Loss / CP) × 100

Direct Percentage Calculation

Open

Find percentage of a given number directly.

Percentage Increase/Decrease

Open

Calculate new value after percentage change.

Find Original from New Value

Open

Find base/original value when final value after change is given.

Discount & Markup Problems

Open

Solve marked price, discount, and selling price problems.

Direct Percentage Calculation

Find percentage of a given number directly.

When to Use: When question asks 'what is X% of Y?'

Step-by-Step Method

Identify the percentage value (X%) and base number (Y).
Convert percentage to decimal: X% = X/100.
Multiply: (X/100) × Y.
Simplify step-by-step: divide Y by 100 first, then multiply by X.

Worked Example

Question: What is 25% of 640?

25% = 25/100 = 1/4
Divide 640 by 4 = 160
Or: 640 ÷ 100 = 6.4, then 6.4 × 25 = 160

Final Answer: 160

Option Analysis

64 = 640 ÷ 10 (wrong: used 10% not 25%)
80 = 640 ÷ 8 (wrong method)
160 is correct: 25% = 1/4 of 640

Common Mistakes

Using percentage as whole number without dividing by 100.
Multiplying instead of dividing for common percentages.
Rounding decimals too early.

Quick Shortcut: 25%=1/4, 50%=1/2, 20%=1/5, 10%=1/10. Use these fractions first!

Practice This Pattern

5 Q 10 Q 15 Q

Generated 10 focused questions for this pattern.

Q1. Two values are in ratio 3:3. If total is 220, find first value.

Answer: 110

Explanation: Step 1: Total parts = 3+3. Step 2: One part = 220/(6). Step 3: First value = 3 parts = 110.

Q2. Two values are in ratio 3:4. If total is 120, find first value.

Answer: 51

Explanation: Step 1: Total parts = 3+4. Step 2: One part = 120/(7). Step 3: First value = 3 parts = 51.

Q3. Two values are in ratio 6:3. If total is 200, find first value.

Answer: 133

Explanation: Step 1: Total parts = 6+3. Step 2: One part = 200/(9). Step 3: First value = 6 parts = 133.

Q4. Two values are in ratio 3:6. If total is 120, find first value.

Answer: 40

Explanation: Step 1: Total parts = 3+6. Step 2: One part = 120/(9). Step 3: First value = 3 parts = 40.

Q5. Two values are in ratio 7:3. If total is 190, find first value.

Answer: 133

Explanation: Step 1: Total parts = 7+3. Step 2: One part = 190/(10). Step 3: First value = 7 parts = 133.

Q6. Two values are in ratio 3:7. If total is 240, find first value.

Answer: 72

Explanation: Step 1: Total parts = 3+7. Step 2: One part = 240/(10). Step 3: First value = 3 parts = 72.

Q7. Two values are in ratio 4:6. If total is 80, find first value.

Answer: 32

Explanation: Step 1: Total parts = 4+6. Step 2: One part = 80/(10). Step 3: First value = 4 parts = 32.

Q8. Two values are in ratio 2:5. If total is 170, find first value.

Answer: 48

Explanation: Step 1: Total parts = 2+5. Step 2: One part = 170/(7). Step 3: First value = 2 parts = 48.

Q9. Two values are in ratio 4:6. If total is 210, find first value.

Answer: 84

Explanation: Step 1: Total parts = 4+6. Step 2: One part = 210/(10). Step 3: First value = 4 parts = 84.

Q10. Two values are in ratio 7:6. If total is 140, find first value.

Answer: 75

Explanation: Step 1: Total parts = 7+6. Step 2: One part = 140/(13). Step 3: First value = 7 parts = 75.