I don't think am right but I hope I can help in any possible way...
3750 for 12 years at 6.5%
multiply 12 * 6.5 = 78% for 12 years
Now we do the following equation -> 3750*0.78 = 2925
Now add 3750 + 2925 = 6675
Hope I'm correct please double check my answer I'm not 100% sure.
Good luck
