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Free Content10 MCQs
Have you ever wondered how discounts work in shops or how much marks you got in an exam? All these things use something called 'percentage'! Percentage helps us understand a 'part' of something when we compare it to the 'whole' thing. It's like cutting a cake into 100 small pieces and saying you ate 25 of them – that's 25 percent!
When you need to find X% of Y, it's often easier to calculate Y% of X. This trick works because percentages are commutative. It can turn a hard problem into a super easy one! Think about 4% of 75. It's tough, right? But what if you think 75% of 4? Easy!
Knowing common fractions and their percentage values by heart saves a lot of time. Instead of multiplying by 100 every time, just remember these friends! Like, 1/2 is 50%, 1/4 is 25%, 1/5 is 20%. This is like knowing your best friend's name without thinking.
To find 10% of any number, just move the decimal point one place to the left! This is super useful for quick estimates or breaking down bigger percentages. For example, 10% of ₹340 is ₹34. Then 20% would be ₹34 + ₹34 = ₹68. It's like finding a small part of your tiffin first.
When a value changes by a percentage, and then changes again by another percentage (like a price first goes up, then down), don't do two separate calculations! Use the formula A + B + (A×B)/100. Here, A and B are the percentage changes (positive for increase, negative for decrease). This trick quickly tells you the total change!
Sometimes, it's easy to find 1% of a number. Just move the decimal two places to the left! Once you know 1%, you can multiply it to find any other percentage. For example, if you know 1% of 500 is 5, then 7% of 500 is simply 7 times 5, which is 35. It's like finding the cost of one tiny candy to know the cost of many.
Imagine you have a big pizza. If you cut it into 100 equal slices, and you eat 10 slices, you've eaten 10 percent (written as 10%) of the pizza! Percentage simply means 'out of 100'. The word 'percent' comes from the Latin phrase 'per centum', which means 'by the hundred'.
The basic idea is always the same: you want to find out how much a 'part' is compared to the 'whole' thing, and then multiply by 100. The formula is: Percentage = (Part / Whole) × 100.
You can easily turn fractions or decimal numbers into percentages.
Going the other way is also simple!
Percentages are very useful for showing how much something has grown or shrunk.
Understanding these ideas will make you a percentage wizard:
Percentages are used everywhere, from calculating interest on loans to figuring out profit and loss in business. Once you get these basic ideas, advanced problems will become much easier!
Basic Percentage Formula
Percentage = (Value / Total Value) × 100Finding Value from Percentage
Value = (Percentage / 100) × Total ValuePercentage Increase
Percentage Increase = ((New Value - Old Value) / Old Value) × 100Percentage Decrease
Percentage Decrease = ((Old Value - New Value) / Old Value) × 100Net Percentage Change (Successive Changes)
Net Change = A + B + (A × B) / 100| Percentage | Fraction | Decimal |
|---|---|---|
| 10% | 1/10 | 0.10 |
| 20% | 1/5 | 0.20 |
| 25% | 1/4 | 0.25 |
| 50% | 1/2 | 0.50 |
| 75% | 3/4 | 0.75 |
| 100% | 1/1 | 1.00 |
Q: Example 1 (Easy): In a class of 50 students, 20 are girls. What percentage of students are girls?
Q: Example 2 (Medium): A shop offers a 15% discount on a toy car that costs ₹400. How much is the discount, and what is the final price?
Q: Example 3 (Harder): Rohan's salary increased by 20% this year. If his new salary is ₹36,000, what was his old salary?
Q: Example 4 (Advanced): A number is first increased by 10% and then decreased by 10%. What is the net percentage change in the number?
You see a cool T-shirt marked at ₹500. There's a '20% off' sign. How much money do you save?
In a T20 cricket match, a team scored 180 runs. Out of these, 60 runs came from boundaries (fours and sixes). What percentage of runs came from boundaries?
Your friend scored 75 marks out of a total of 120 marks in a Math test. What is her percentage score?
Your dad says he'll increase your ₹200 pocket money by 10%. How much extra money will you get, and what will be your new pocket money?
If 40% of a number is added to 60, the result is the number itself. What is the number?
If 40% of a number is 60, what is 75% of that number?
The population of a town increased by 10% in the first year and decreased by 10% in the second year. If the present population is 49,500, what was the population 2 years ago?
In an exam, 60% students passed in English, 70% passed in Hindi, and 40% passed in both. What percentage of students failed in both subjects?
1What is 20% of 150?
2Convert the fraction 3/4 to a percentage.
3If an item costs ₹500 and has a 10% discount, what is the discount amount?
4What percentage of 200 is 40?
5If a number increases from 80 to 100, what is the percentage increase?
6A student scored 60% marks in an exam. If the maximum marks were 750, how many marks did he score?
7If 30% of a number is 90, what is the number?
8A salary is first increased by 20% and then decreased by 20%. What is the net percentage change in salary?
9If 80% of students passed an exam and 120 students failed, how many students appeared for the exam?
10A shopkeeper increased the price of an article by 25% and then allowed a discount of 20%. What is the overall percentage change in the price of the article?
When you need to find X% of Y, it's often easier to calculate Y% of X. This trick works because percentages are commutative. It can turn a hard problem into a super easy one! Think about 4% of 75. It's tough, right? But what if you think 75% of 4? Easy!
Knowing common fractions and their percentage values by heart saves a lot of time. Instead of multiplying by 100 every time, just remember these friends! Like, 1/2 is 50%, 1/4 is 25%, 1/5 is 20%. This is like knowing your best friend's name without thinking.
To find 10% of any number, just move the decimal point one place to the left! This is super useful for quick estimates or breaking down bigger percentages. For example, 10% of ₹340 is ₹34. Then 20% would be ₹34 + ₹34 = ₹68. It's like finding a small part of your tiffin first.
When a value changes by a percentage, and then changes again by another percentage (like a price first goes up, then down), don't do two separate calculations! Use the formula A + B + (A×B)/100. Here, A and B are the percentage changes (positive for increase, negative for decrease). This trick quickly tells you the total change!
Sometimes, it's easy to find 1% of a number. Just move the decimal two places to the left! Once you know 1%, you can multiply it to find any other percentage. For example, if you know 1% of 500 is 5, then 7% of 500 is simply 7 times 5, which is 35. It's like finding the cost of one tiny candy to know the cost of many.
Percentage = (Value / Total Value) × 100Value = (Percentage / 100) × Total ValuePercentage Increase = ((New Value - Old Value) / Old Value) × 100+2 more formulas below