Answer: 188 months
Step-by-step explanation:
Principal = $129 000
Payment = $1000
Mortgage % = 5.15
Since,
Number of Months = log (1+[rate/(Payment/Principal)-rate] / log (1 + rate)
Also,
rate = 5.15/1,200 = 0.004292
Number of Months = log (1 + [0.004292/(1,000/129000) -0.004292] / log(1+0.004292)
Number of Months = log ( 1 + 0.004292/ ((0.007752 -0.004292) / log (1.004292)
Number of Months = log ( 1 + (0.004292/0.00346))/ log (1.004292)
Number of Months = log (1 + 1.240) / log (1.004292)
Number of Months = log (2.240) / log (1.004292)
Number of Months = 0.3502 / 0.001860
Number of Months = 188.28 months
Approximation to whole month,
Number of months = 188 Months.