For this case, what you need to know is that you have a number in the form of a percentage.
To write it as a number you must divide this value by 100.
We have then:
(280%) / (100%) = 2.8
Equivalently in the form of fraction we have:
2.8 = (28) / (10)
2.8 = 14/5
Answer:
280% as a fraction or mixed number in simplest form is:
14/5
or
2.8