31/99 as a percentage is 31.31%. This value is the rounded result you get when you look at the fraction in a percent form, and it’s useful for quick comparisons.
The fraction 31/99 is a repeating decimal (0.313131…) that lines up nicely with its percent representation. Because the digits repeat, the percentage also shows a repeating pattern before we round it to two decimal places.
In everyday terms, if you had 31 items out of a total of 99, you’d be holding about 31.31% of the whole set. This makes it easy to estimate shares, scores, or any situation where a simple percent helps convey the size of a part relative to the whole.