All Exams: Percentage — Concept Guide + 10 MCQs

This guide covers the complete concept of Percentage as tested in All Exams 2026, followed by 10 practice MCQs with detailed explanations.

Percentage — Quick Concepts & Tricks

Percentage is one of the most frequently tested topics. It also forms the base for topics like profit/loss, simple interest, and data interpretation.

Key Percentage Formulas

ConceptFormula
X% of Y(X × Y) / 100
A is what % of B(A/B) × 100
% increase[(New - Old)/Old] × 100
% decrease[(Old - New)/Old] × 100
Successive % changes (a% then b%)Net = a + b + ab/100

Fraction-Percentage Conversion (Must Memorise)

  • 1/2 = 50%, 1/3 = 33.33%, 1/4 = 25%, 1/5 = 20%
  • 1/6 = 16.67%, 1/7 = 14.28%, 1/8 = 12.5%, 1/9 = 11.11%
  • 1/10 = 10%, 1/11 = 9.09%, 1/12 = 8.33%

Practice MCQs — Percentage

Attempt these questions after reading the concept above. Suggested time: 15 minutes.

Q1. What is 15% of 240?

  • A. 36
  • B. 32
  • C. 30
  • D. 24
Explanation: 15% of 240 = (15/100) × 240 = 36.

Q2. If a number is increased by 20% and then decreased by 20%, the net change is:

  • A. No change
  • B. 4% decrease
  • C. 2% decrease
  • D. 4% increase
Explanation: Let number = 100. After 20% increase: 120. After 20% decrease: 120 × 0.8 = 96. Net change = 4% decrease.

Q3. A shopkeeper marks his goods 40% above cost price and gives 10% discount. Find his profit %:

  • A. 26%
  • B. 30%
  • C. 24%
  • D. 28%
Explanation: CP = 100, MP = 140. SP = 140 × 0.9 = 126. Profit% = 26%.

Q4. What is 15% of 240?

  • A. 36
  • B. 32
  • C. 30
  • D. 24
Explanation: 15% of 240 = (15/100) × 240 = 36.

Q5. If a number is increased by 20% and then decreased by 20%, the net change is:

  • A. No change
  • B. 4% decrease
  • C. 2% decrease
  • D. 4% increase
Explanation: Let number = 100. After 20% increase: 120. After 20% decrease: 120 × 0.8 = 96. Net change = 4% decrease.

Q6. A shopkeeper marks his goods 40% above cost price and gives 10% discount. Find his profit %:

  • A. 26%
  • B. 30%
  • C. 24%
  • D. 28%
Explanation: CP = 100, MP = 140. SP = 140 × 0.9 = 126. Profit% = 26%.

Q7. What is 15% of 240?

  • A. 36
  • B. 32
  • C. 30
  • D. 24
Explanation: 15% of 240 = (15/100) × 240 = 36.

Q8. If a number is increased by 20% and then decreased by 20%, the net change is:

  • A. No change
  • B. 4% decrease
  • C. 2% decrease
  • D. 4% increase
Explanation: Let number = 100. After 20% increase: 120. After 20% decrease: 120 × 0.8 = 96. Net change = 4% decrease.

Q9. A shopkeeper marks his goods 40% above cost price and gives 10% discount. Find his profit %:

  • A. 26%
  • B. 30%
  • C. 24%
  • D. 28%
Explanation: CP = 100, MP = 140. SP = 140 × 0.9 = 126. Profit% = 26%.

Q10. What is 15% of 240?

  • A. 36
  • B. 32
  • C. 30
  • D. 24
Explanation: 15% of 240 = (15/100) × 240 = 36.