13.5/1.3 = 10.38, approx.
You seem to be unaware of the fact that you could have obtained the answer much more easily and quickly by using the calculator that comes as part of your computer.
13.5
5.625
0.1407
135
135
135
They can't. 135 can be divided by 3, 5 and 9.
135
19.2857
19.2857
79 Divided by 135 is .5851851851852 Or 79 is 58.51% of 135
0.12