24.39% is what 20/82 equals when expressed as a percentage.
The fraction 20/82 can be reduced to 10/41, but the decimal value stays the same, giving the same percentage result. When you see a number like this in a report or a chart, it means that roughly one quarter of the whole is represented.
Knowing the percentage helps you compare it quickly with other values. For example, if a class of 82 students has 20 who passed a test, you can say about 24.39% of the class succeeded. This makes it easier to understand the size of the group at a glance.