What is 25 percent of 81?
Solution for 'What is 25% of 81?'
In the following example consider that:
- The percentage figure is represented by X%
- The whole amount is represented by W
- The portion amount or part is represented by P
The following question is of the type "How much X percent of W", where W is the whole amount and X is the percentage figure or rate".
Let's say that you need to find 25 percent of 81. What are the steps?
Step 1: first determine the value of the whole amount. We assume that the whole amount is 81.
Step 2: determine the percentage, which is 25.
Step 3: Convert the percentage 25% to its decimal form by dividing 25 into 100 to get the decimal number 0.25:
25100 = 0.25
Notice that dividing into 100 is the same as moving the decimal point two places to the left.
25.0 → 2.50 → 0.25
Step 4: Finally, find the portion by multiplying the decimal form, found in the previous step, by the whole amount:
0.25 x 81 = 20.25 (answer).
The steps above are expressed by the formula:
P = W × X%100
This formula says that:
"To find the portion or the part from the whole amount, multiply the whole by the percentage, then divide the result by 100".
The symbol % means the percentage expressed in a fraction or multiple of one hundred.
Replacing these values in the formula, we get:
P = 81 × 25100 = 81 × 0.25 = 20.25 (answer)
Therefore, the answer is 20.25 is 25 percent of 81.