High School Math
posted by Jasson .
I'm helping my little sister in her math homework. I just got stuck in this problem. Can anyone please help us out. I'm guessing it's letter C. Am I correct?
A small company borrows $50,000 at 11% compounded monthly. The loan is due in 4 years. How much interest will the company pay? Round to the nearest cent.
A)$26,776.12
B)$27,175.47
C)$27,479.90
D)$77,479.9

How did you make a guess for your sister?
Did she work it out, in which case there should be details of the work.
You won't be helping her if you gave her the right answer without telling her why or how.
Can she post her answer? 
well I came up with because I just guessed it that's why i'm here to ask for help becuase I just can't come up with the actual answer. I come up with 22,000
50,000x.11=5500
5500/4=22,000
what am I doing wrong here? 
Every month the principal is increased by (.11/12)principal
or
principal = original principal [1 +(.11/12)]^48 because 4 years is 48 months
so
principal after 48 months = 50,000[1.091666667]^48
=77479.90
and
77479.9050000 = 27479.90