4/5 or 13/15.
Let us try to make the bottom of the first fraction to be 15, by multiplying the bottom 5 by 3, and of course we would multiply the top also.
(4/5)*(3/3) = 12/15
So we are now comparing: 12/15 and 13/15
We can see that 13/15 is greater, because it has a higher numerator.
So 13/15 is greater than 4/5
OR
4/5 13/15 Cross Multiply
4*15 13*5
60 65
60 < 65
Implies that 4/5 is less than 13/15 and hence 13/15 is greater than 4/5.
OR
Use your calculator and convert both to decimal
45 13/15
0.80 0.8667
You can see that 13/15 is greater than 4/5.
