Example 1
What is 10% of 450?
- 10% of 450 = 10 × 450 ÷ 100
- = 4500 ÷ 100
- = 45
Answer: 45
Percentage Questions with Worked Solutions
Learn percentage questions step by step: percent of a number, what percent one number is of another, and successive change, with worked examples.
How to solve percentage questions
Percent of a number
Multiply the number by the percent and divide by 100. 10% is a tenth of the number and 50% is half of it.
What percent one number is of another
Divide the part by the whole and multiply by 100. The number after 'of' is always the whole.
Successive percentage change
After a rise of a% and then a fall of b%, the net change is a − b − (a × b ÷ 100) percent. A negative result is an overall fall.
Worked examples
Example 2
What percent of 120 is 30?
- Percent = part ÷ whole × 100
- = 30 ÷ 120 × 100
- = 25%
Answer: 25%
Example 3
The price of a phone rises by 10% and then falls by 20%. By what percent does the price fall overall?
- Start from 100: after a 10% rise it is 100 + 10 = 110
- After a 20% fall: 110 − 20% of 110 = 110 − 22 = 88
- Fall overall = 100 − 88 = 12%
Answer: 12%