15 ÷ 36 equals 41.67% when expressed as a percentage. This is the rounded figure you get for the fraction 15/36.
The fraction can be simplified to 5/12, which still represents the same part of a whole. Whether you keep it as 15/36 or 5/12, the percentage value stays the same.
Knowing the percentage helps you compare this portion to other numbers more easily, such as seeing that it’s a little less than half of a whole. It’s a handy way to understand how big 15 out of 36 really is.