PERCENTAGES i

Question 1

Percentage to Fraction
What is the formula?

Answer 1

Percentage ÷ 100
Example: 25% = 25 ÷ 100 = 1/4

Question 2

Percentage to Decimal
What is the formula?

Answer 2

Percentage ÷ 100
Example: 40% = 40 ÷ 100 = 0.4

Question 3

Fraction to Percentage
What is the formula?

Answer 3

Fraction × 100
Example: 3/5 × 100 = 60%

Question 4

Percentage of a Quantity
What is the formula?

Answer 4

(Percentage ÷ 100) × Quantity

Example: 20% of 80 = (20 ÷ 100) × 80 = 16

Question 5

Fraction of a Quantity
What is the formula?

Answer 5

Fraction × Quantity

Example: 3/4 of 60 = 3/4 × 60 = 45

Question 6

Percentage Change
What is the formula?

Answer 6

Change ÷ Original) × 100%

Change = New – Old

Example: From 50 to 60 → (10 ÷ 50) × 100 = 20% increase

Question 7

Percentage Error
What is the formula?

Answer 7

(|Measured – Actual| ÷ Actual) × 100%
Always use positive difference

Example: Measured = 52, Actual = 50 → (2 ÷ 50) × 100 = 4%