what is the difference between the compound interest and interest is compound 5 month and the simple interest on a sum of rupees 12000 for1 1/4 year at 12% per annum

Here Time=15 months .Rate =12%p.a and principal =12000rs.
First we calculate Simple interest effective rate .
We know rate=12% for 12 months means 1% for 1months means 15% for 15months.
Now we will calculate effective rate of compound interest.
There will be 3 cycle of 5% each which will be equivalent to 15.7625%.
Now the difference between SI and CI =(15.7625-15)%=0.7625%of 12000 which will be equal to 91.5 RS.