Formula to calculate percentage

What is a percentage?

A percentage is a way to define a part, or fraction of a total.

When we talk about percentages, we should always ask ourselves the following: "the percentage of what?". Saying 50% without specifying 50% of what, makes no sense. However, if we say "the 50% 50\% of 80 80 " is 40 40 . In summary, the percentage represents what part of 100 100 is the number in question.

The percentage symbol is % \% :
when we want to express that a%a\%
We will write it as: a100a \over 100

To solve percentage problems, we will use the following formula

Percentage valueInitial amount=The percentage100 \frac{Percentage~value}{Initial~amount}=\frac{The~percentage}{100}

Percentage value: is the actual value that this percentage represents.

Initial amount: is the initial figure before being changed.
Percentage: is the percentage of change.

B - To solve percentage problems, we will use the following formula

You can use this formula for any percentage exercise, as long as you note the data correctly, and verify what has been asked.


Practice Percentage

Examples with solutions for Percentage

Exercise #1

Calculate 15% of 100:

Step-by-Step Solution

To find 15% of 100, you can convert the percentage to a decimal by dividing by 100:

15%=15100=0.15 15\% = \frac{15}{100} = 0.15

Next, multiply this decimal by 100:

0.15×100=15 0.15 \times 100 = 15

Thus, 15% of 100 is 15.

Answer

15 15

Exercise #2

Calculate 8% of 100:

Step-by-Step Solution

To find 8% of 100, first convert the percentage to a decimal by dividing by 100:

8%=8100=0.08 8\% = \frac{8}{100} = 0.08

Then, multiply this decimal by 100:

0.08×100=8 0.08 \times 100 = 8

Hence, 8% of 100 is 8.

Answer

8 8

Exercise #3

Calculate 45% of 100:

Step-by-Step Solution

To find 45% of 100, you can multiply the percentage as a decimal by the whole number. First, convert 45% into a decimal. This is done by dividing by 100: 45%=45100=0.45 45\% = \frac{45}{100} = 0.45 .

Then, multiply this decimal by 100: 0.45×100=45 0.45 \times 100 = 45 .

Therefore, 45% of 100 is 45 45 .

Answer

45 45

Exercise #4

Calculate 35% of 100:

Step-by-Step Solution

To find 35% of 100, first convert the percentage into a decimal by dividing by 100: 35%=35100=0.35 35\% = \frac{35}{100} = 0.35 .

Then, multiply this decimal by 100: 0.35×100=35 0.35 \times 100 = 35 .

Therefore, 35% of 100 is 35 35 .

Answer

35 35

Exercise #5

Calculate 25 out of 100 as a percentage:

Step-by-Step Solution

In order to determine what percentage 25 is out of 100, we use the following formula:

Percentage=PartWhole×100% \text{Percentage} = \frac{\text{Part}}{\text{Whole}} \times 100\%

.

We begin by substituting in the known values:

Percentage=25100×100%=25% \text{Percentage} = \frac{25}{100} \times 100\% = 25\%

.

Thus, 25 out of 100 is 25% 25\% .

Answer

25%

Exercise #6

Calculate 75 out of 100 as a percentage:

Step-by-Step Solution

In order to determine what percentage 75 is out of 100, we use the following formula:

Percentage=PartWhole×100% \text{Percentage} = \frac{\text{Part}}{\text{Whole}} \times 100\%

.

We begin by substituting in the known values:

Percentage=75100×100%=75% \text{Percentage} = \frac{75}{100} \times 100\% = 75\%

.

Thus, 75 out of 100 is 75% 75\% .

Answer

75%

Exercise #7

Calculate 10 out of 100 as a percentage:

Step-by-Step Solution

In order to determine what percentage 10 is out of 100, we use the following formula:

Percentage=PartWhole×100% \text{Percentage} = \frac{\text{Part}}{\text{Whole}} \times 100\%

.

We substitute in the known values:

Percentage=10100×100%=10% \text{Percentage} = \frac{10}{100} \times 100\% = 10\%

.

Thus, 10 out of 100 is 10% 10\% .

Answer

10%

Exercise #8

Calculate 40 out of 100 as a percentage:

Step-by-Step Solution

In order to determine what percentage 40 is out of 100, we use the following formula:

Percentage=(PartWhole)×100 \text{Percentage} = \left( \frac{\text{Part}}{\text{Whole}} \right) \times 100

We begin by substituting in the known values:

Percentage=(40100)×100 \text{Percentage} = \left( \frac{40}{100} \right) \times 100

We then proceed to solve the expression:

Percentage=0.4×100 \text{Percentage} = 0.4 \times 100

Percentage=40 \text{Percentage} = 40

Thus, 40 out of 100 is 40%.

Answer

40%

Exercise #9

Calculate 65 out of 100 as a percentage:

Step-by-Step Solution

To find what percentage 65 is out of 100, use the formula:

Percentage=(PartWhole)×100 \text{Percentage} = \left( \frac{\text{Part}}{\text{Whole}} \right) \times 100

Substitute the given values:

Percentage=(65100)×100 \text{Percentage}=\left(\frac{65}{100}\right)\times100

Solve the expression:

Percentage=0.65×100 \text{Percentage}=0.65\times100

Percentage=65 \text{Percentage}=65

So, 65 out of 100 is 65%.

Answer

65%

Exercise #10

Determine 20% of 100:

Step-by-Step Solution

In order to determine 20% of 100, we begin by converting the percentage into a decimal and then proceed to multiply by the whole number. First, convert 20% to a decimal: 20%=0.2 20\% = 0.2

Next, multiply this decimal by 100 to find the percentage of the whole number: 0.2×100=20 0.2 \times 100 = 20

Thus, 20% of 100 is 20 20 .

Answer

20 20

Exercise #11

Determine 95% of 100:

Step-by-Step Solution

In order to calculate 15% of 100, start by converting the percentage into a decimal. Convert 15% to a decimal: 95%=0.95 95\% = 0.95

Then multiply the decimal by 100 to find the percentage value: 0.95×100=95 0.95 \times 100 = 95

So, 95% of 100 is 95 95 .

Answer

95 95

Exercise #12

Calculate 50% of 100:

Step-by-Step Solution

In order to determine 50% of 100, we first convert the percentage into a decimal. Convert 50% to a decimal: 50%=0.5 50\% = 0.5 .

Next, multiply the decimal by 100 to get the percentage value: 0.5×100=50 0.5 \times 100 = 50 .

Therefore, 50% of 100 is 50 50 .

Answer

50 50

Exercise #13

Calculate 75% of 100:

Step-by-Step Solution

In order to calculate 75% of 100, we must first convert the percent into a decimal. Convert 75% to a decimal: 75%=0.75 75\% = 0.75 .

Then multiply by the whole number: 0.75×100=75 0.75 \times 100 = 75 .

Therefore, 75% of 100 is 75 75 .

Answer

75 75

Exercise #14

Calculate 30 out of 100 as a percentage:

Step-by-Step Solution

In order to determine what percentage 30 is out of 100, you can use the following formula:

Percentage=PartWhole×100 \text{Percentage} = \frac{\text{Part}}{\text{Whole}} \times 100

We begin by substituting the given values into the formula:

Percentage=30100×100 \text{Percentage} = \frac{30}{100} \times 100

We then proceed to simplify the expression:

Percentage=30% \text{Percentage} = 30\%

Therefore, 30 out of 100 is 30%.

Answer

30%

Exercise #15

Calculate 50 out of 100 as a percentage:

Step-by-Step Solution

In order to determine what percentage 50 is out of 100, we use the following formula:

Percentage=PartWhole×100 \text{Percentage} = \frac{\text{Part}}{\text{Whole}} \times 100

Input the known values into the formula:

Percentage=50100×100 \text{Percentage} = \frac{50}{100} \times 100

This simplifies to:

Percentage=50% \text{Percentage} = 50\%

Hence, 50 out of 100 corresponds to 50%.

Answer

50%