9/20
No.
No.
11/20 or 0.55
Yes, four fifths is 80% and three fourths would be 75%.
Twenty four fifths is four and four fifths. So if you take three away, that leaves one and four fifths.
25
six and three-fourths
three and one-forth
Assuming that you mean "fifths", the answer is three fifths.
1 7/20
4/5