Yes - it simplifies to 7 over 24
21 over 72, or 7 over 24 (simplified)
47/72 is already simplified
8 over 24 is not the simplest form. The simplest form is 1/3. However, it is a simplified form of 16/48 or 24/72, for example.
It is: 72/96 = 3/4 simplified
-13/72 cannot be simplified.
55/72
No.
21 over 24 simplified is 7/8.
72/100 = 18/25
72/83 is simplified.
It is 72/100, which can be simplified, if required.