21/74 expressed as a percentage is 28.38%. This number tells you how much of a whole 21 parts out of 74 represent when you think in terms of hundredths.
The fraction 21/74 can show up in real‑world situations like a class test where a student gets 21 correct answers out of 74 questions. Saying the result is 28.38% makes it easy to compare with other scores that are already in percent form.
Because the decimal was rounded to two places, the true value is very close to 28.38%, but not exactly that number. Rounding keeps the figure simple to read and use without losing much accuracy.