5/6
1/15
15/18 can be reduced to 5/6
15/72 = 5/24 reduced
11/15 cannot be reduced further.
6 over 8 reduced = 3/4
6 over 18 is reduced to 1/3
6/25 cannot be reduced.
It is: 5/12 reduced
15 over 30 reduced to lowest terms is 1/2
The fraction 4/15 cannot be reduced any more.
15 and 6 are both divisible by 3. 15/3 is 5, and 6/3 is 2. 5/2 cannot be reduced further, so 15/6 in its simplest form would be 5/2.