21/35 as a percentage is 60.00%. This rounded figure tells you how much of a whole the fraction represents when expressed in percent form.
The fraction 21/35 can be reduced to 3/5, which is the same proportion. Whether you write it as 21/35, 3/5, or 60.00%, the value stays the same.
Percentages like 60.00% are useful for quick comparisons. For example, if you scored 21 out of 35 points on a test, you earned 60.00% of the possible marks.
