Notes on Percentage | Grade 7 > Compulsory Maths > Percentage | KULLABS.COM

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#### Percent

Percent means parts per hundred or out of hundred. The symbol of a percent is %.

For example, 25% means 25 per 100 or, $$\frac{25}{100}$$

Percentage is a fraction written with a denominator 100.

Conversion of fraction or decimal into percent

For the conversion of a fraction or decimal into percent multiply it by 100 and put the symbol % to the product. For example,

$$\frac{2}{5}$$ =$$\frac{2}{5}$$ × 100 % = 40 %

0.3 = 0.3× 100 % = 30 %

Conversion of percent into fraction or decimal

For the conversion of percent into fraction or decimal, divide it by 100 and remove the % symbol. For example,

20% =$$\frac{20}{100}$$ =$$\frac{1}{5}$$

32% =$$\frac{32}{100}$$ = 0.32

To express a given quantity as the percent of whole quantity

For the expression of the given quantity as the fraction of the whole quantity, then multiply the fraction by 100%. For examples,

20 as the percent of 80 =$$\frac{20}{80}$$ × 100 = 25%

To find the value of given percent of a quantity

If this case is given, then multiply the quantity by the given percent. Then, convert the percent into a fraction and simplify. For example,

25% of Rs.250 = 25%× 250 =$$\frac{25}{100}$$× 250 = Rs. 62.5 ans.

To find a quantity whose value of certain percent is given

If this case is given, we can suppose the whole quantity by a variable such as x. Then we can form an equation and by solving the equation we can find the value of x. For example,

If 20% of a sum is Rs. 80. Find the sum

Here, Let the sum be Rs.x

Now, 20% of x = Rs.80

or, $$\frac{20}{100}$$× x = Rs. 80

or, $$\frac{x}{5}$$ = Rs.80

or, x =Rs. 80 × 5 = Rs.400

• Percentage is a fraction written with a denominator 100.
• For the conversion of a fraction or decimal into percent multiply it by 100 and put the symbol % to the product.
• For the conversion of percent into fraction or decimal, divide it by 100 and remove the % symbol.
.

### Very Short Questions

Solution:

Here,
the initial rate of a price = Rs 50 per liter
The new rate of a price = rs 55 per liter
∴ Increment in the rate price = Rs 55 - Rs  50 = rs 5
Now,
the increment percentage = $$\frac{Increment \; price}{Initial \; price}$$ × 100%
= $$\frac{Rs \; 5}{Rs \; 50}$$ × 100%
= 10%
So, the rate of a price of petrol is increased by 10%

Solution:

Let, the total number of students in the school be x.
Here,
or, 75% of x = 225
or, $$\frac{75}{100}$$ × x = 225
or, $$\frac{3x}{4}$$ = 225
or, x = $$\frac{4 × 225}{3}$$
or, x = 300
So, the total number of students in the school is 300,
Again,
Number of girls = 300 - 225
So, there are 75 girls in the school.

0%

70%
75%
65%
80%

33%
39%
37%
35%

4.8%
8.4%
84%
48%

5.06
0.56
5.6
05.6

20%
10%
15%
5%

55
50
45
60

Rs 16.00
Rs 6000
Rs 1600
Rs 16,000

60%
70%
80%
75%

60%
75%
80%
90%

270
290
250
230

## ASK ANY QUESTION ON Percentage

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