In: Finance
| Loan principal after the 60 the monthly payment(ie. 5*12=60 mths.)= 100000 | 
| Monthly payment from end of 61st month can be calculated as follows: | 
| Loan principal= 100000 | 
| Pmt.--Monthly pmt. Needs to be found out-- | 
| r= Rate of interest= 5%/12=0.4167% or 0.004167 p.m. | 
| n= 15 yrs. *12=180 mths. | 
| so, using the PV of ordinary annuity formula, | 
| 100000=Pmt.*(1-1.004167^-180)/0.004167 | 
| so, the monthly pmt. Will be | 
| 100000/((1-1.004167^-180)/0.004167)= | 
| 790.81 | 
| 
 a) New equivalent effective monthly rate on the loan  | 
| As it is compounded semi-annually, we will find the effective semi-annual rate & then divide by 6 , to get the mthly. Rate-- | 
| (1+r)^2-1=5.5% | 
| so, effective s/a r=2.71319% per s/a period | 
| ie. 2.71319%/6= | 
| 0.004522 | 
| p.m. | 
| 0.4522% | 
| b.Loan balance o/s after another 5 yrs. At original interest rates----ie. Another 60 mths. (10 yrs. From original time 0) | 
| Original loan principal= 100000; Mthly. Pmt= 790.81 ,mthly r= 0.4522%, n=60 mths. | 
| Loan balance=FV of the original loan amt.-FV of the 60 mthly. annuities | 
| ie. (100000*(1+0.4167%)^60)-(790.81*((1+0.4167%)^60-1)/0.4167%)= | 
| 74557.98 | 
| c. So, from b. above, Loan balance pending (at end of 10 yrs. From t=0) is $ 74558 (rounded-off) | 
| After the repayment of a lump sum of $10,000 immediately,the loan balance becomes | 
| 74558-10000=64558 | 
| so, equating the above PV of the loan , to the PV of the annuities of $ 1000 | 
| at the new monthly rate of 0.4522%---- for n no.of mths. | 
| 64558=1000*(1-(1+0.4522%)^-n)/0.4522% | 
| solving for n, | 
| no.of months = 76.5135 mths. | 
| ie. No.of months of full repayment of $ 1000 =76 | 
| so, in 76 complete mths. He would have paid | 
| 1000*(1-(1+0.4522%)^-76)/0.4522%= | 
| 64195 | 
| & the smaller payment in the subsequent month will be | 
| 64558-64195= | 
| 363 |