# Percentage

## Comparing Quantities of Class 7

The term "percentage" was taken from the Latin word "per centum," meaning "hundred." Percents are fractions with 100 as the denominator. In other words, it is a relationship between the whole and the part, where the value of the whole or part is always taken as 100.

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## What is the Percentage?

A percentage is a ratio or fraction in which the value of the whole is always 100. For example, if ram scored 40% on his English test, that means he scored 40 out of 100. It is written as 40/100 in fraction form, and the ratio is 40:100.

### Percentage Formula

To calculate the percentage, we have to divide the value by the total value and then multiply the resultant by 100.

Formula = (Value/Total value) × 100

Example: 3/5 × 100 = 0.6 × 100 = 60 per cent

### How to calculate the percentage of a number?

To calculate the percentage of a number, then, we will use a different formula such as:

A% of Number = X

whereas X is the percentage.

If the % sign is removed, then we need to express the formula given above

A/100 * Number = X

Example: Calculate 10% of 80.

Let 10% of 80 = X

10/100 * 80 = X

X = 8

### How to Calculate Percentage Increase?

Percentage increase refers to the change in value in an exchange rate as it increases over a period of time. For example, an increase in population, an increase in the number of bacteria on a surface, etc. The percentage increase can be calculated using the following formula:

Percentage increase = (increase value - original value)/original value × 100

### How to Calculate Percentage Decrease?

Percentage decrease refers to the change in value in an exchange rate when it decreases over a period of time. For example, a decrease in rainfall levels, a decrease in the number of Covid patients, etc. The percentage decrease can be calculated using the following formula:

Percent decrease = (Original Value-decrease Value)/Original Value × 100

### Percentage Difference Formula ### Percentage Formula Examples

Q1. Find the number if 14% of 30% of a number is 6.

Ans. Let X be the required number.

Therefore, as per the given question,

(14/100) × (30/100) × X = 6

So, X = (6 × 100 × 100) / (14 × 30)

= 142.8

Q2. What percentage of 1/7 is 1/35?

Ans. Let X% of 1/7 be 1/35.

[(1/7) / 100] × X = 1/35

X = (1/35) × (7/1) × 100

X = 20%

Q3. Which number is 40% less than 90?

Ans. Required number = 60% of 90

= (90 x 60)/100

= 54

Q4. A fruit seller had some apples. He sells 60% apples and still has 520 apples. Originally, he had how many apples?

Ans. Let he had N apples, originally.

Now, as per the given question, we have;

(100 – 60)% of N = 520

⇒ (40/100) × N = 520

⇒ N = (520 × 100/40) = 1300