To find out what number 21 is 75 percent of, you can use a simple algebraic approach. Let’s denote the unknown number as X.
We know that 75 percent can be written as a fraction: 75% = 75/100 = 0.75. According to the problem, 21 is equal to 75 percent of X, which can be mathematically represented as:
21 = 0.75 * X
To isolate X, divide both sides of the equation by 0.75:
X = 21 / 0.75
Now, perform the calculation:
X = 21 / 0.75 = 28
Thus, 21 is 75 percent of 28. So, the answer to the question is:
X = 28
Therefore, if you’re ever wondering what number corresponds to a certain percentage, just set up a simple equation and solve for the unknown. In this case, to check your work: if you calculate 75% of 28, you will indeed get 21, confirming that your solution is correct.