Maths-2 Percentage: Questions and Step-by-Step Solutions for Competitive Exams SSC, BSSC, Bank, Railways

Maths-6 Percentage: Questions and Step-by-Step Solutions for Competitive Exams SSC, BSSC, Bank, Railways

What Is a Percentage?

Percentage means “out of 100.”
It’s a way to show how much of something you have compared to the whole.

Example:

If you got 80 marks out of 100, we say you scored 80%.
So, 80% = 80 out of 100.

🍕 Let’s Learn with Pizza!

Imagine a pizza 🍕 cut into 100 tiny pieces.

• If you eat 25 pieces, you ate 25% of the pizza.
• If your friend eats 50 pieces, they ate 50% of the pizza.
• If your family eats 100 pieces, they ate 100% — the whole pizza!

Understanding Percentage: step by step from the very basics of Percentage.

• “Percent” means “per hundred”.
• It shows a number as a fraction of 100.
• Example: 25% = 25 out of 100 = 25/100 = 1/4.

Basic Formula

Percentage=Value/Total Value×100

Value=Percentage×Total Value/100

Step 1: Simple Conversions

1. Convert 25% into fraction → 25/100=1/4.
2. Convert 0.75 into % → 0.75×100=75%.
3. Convert 3/20 into % → (3/20)×100=15%

Step 2: Finding % of a Number

• Example: Find 20% of 250.

20/100×250=50

Step 3: Finding Value from %

• Example: 15% of a number is 60. Find the number.

Number=60×100/15=400

Step 4: Percentage Increase & Decrease

• Increase = Increase/Original×100
• Decrease = Decrease/Original×100

✔ Example: Price rises from 200 to 250.
Increase = 50.

%Increase=50/200×100=25%

✔ Example: Marks drop from 80 to 60.
Decrease = 20.

%Decrease=20/80×100=25%

Step 5: Successive Percentage Change

If a value is changed by x% and then y%

Net % Change = x + y + {xy}/100

✔ Example: Price increases by 20% and then 10%.

20+10+(20×10)/100=32% increase

Step 6: In Exams

1. Profit & Loss: % profit = Profit/CostPrice×100
2. Marks: % marks = Marks Obtained/TotalMarks×100
3. Population Growth: Apply the successive % change formula.
4. Discounts: % discount = Discount/MarkedPrice×100

Quick Practice (Basic)

1. Convert 2/5 into %.
2. Find 30% of 480.
3. If 25% of a number is 80, find the number.
4. A man’s salary increases from ₹20,000 to ₹25,000. Find % increase.
5. Successive change: +10% and –20%. Find net % change.