21/72 as a percentage is 29.17%. This number shows how much of a whole 21 parts out of 72 represent, rounded to two decimal places.
If you reduce the fraction first, 21/72 simplifies to 7/24. The simplified form makes it easier to see the size of the part compared to the whole, and it still converts to the same percentage.
In everyday situations, you might use this percentage to compare portions, such as a recipe that calls for 21 out of 72 ounces of an ingredient, or to understand a score that is 21 points out of a possible 72.
Remember, the percentage tells you the same information as the fraction, just on a scale of 0 to 100, which is often quicker to read and compare.