Original practice · fully worked
Original variant: monthly midperiod payments with later equipment draws
A studio owes 2,000 at month 0, borrows another 500 at months 3, 9, and 15, and pays X at the middle of each month for 18 months. The balance is zero at month 18. At 1% effective per month, determine X.
- A
180.00 - B
195.00 - C
204.68 - D
215.00 - E
230.00
Answer and calculation
Present-valuing the four advances and 18 half-month-shifted payments gives X = 204.68, choice C.
Setup
Setup
Month zero is the value date; later equipment draws are discounted by their exact month counts.
PVD=2000+500(v3+v9+v15)=3373.1397 Model
Model
A payment in month k occurs at k minus one-half, so the repayment annuity has a half-month timing shift.
PVP=Xk=1∑18vk−1/2=16.480056X Compute
Compute
The advance value is 3,373.1397 and the payment factor is 16.480056.
X=3373.1397/16.480056=204.6801 Answer
Answer
Their quotient is a monthly payment of 204.68, corresponding to choice C.
X=204.68(C)