Question 1177707
the nominal interest rate is 12% per year.
the effective interest rate is 1% per month.
this yields an effective interest rate of ((1.01)^12 -1) * 100 = 12.68250301% per year.


your growth factor per year is (1.01)^12 = 1.1268250301.


you start with 10,000
one year later, the value is equal to 10,000 * 1.1268250301 = 11,268.21503.
you add 10,000 to that to get 21,268.21503.
one year later, the value of that is equal to 21,268.21503 * 1.1268250301 = 23,965.59679.
you add 10,000 to that to get 33,965.59679.
one year later, the value of that is equal to 33,965.59679 * 1.1268250301 = 38,273.28462.


you could also have used a financial calculator to get the same results.
one such calculator can be found at <a href = "https://arachnoid.com/finance/index.html" target = "_blank">https://arachnoid.com/finance/index.html</a>


the inputs to this calculator are shown below.


<img src = "http://theo.x10hosting.com/2021/032711.jpg">


the output from this calculator is shown below.


<img src = "http://theo.x10hosting.com/2021/032712.jpg">


since you are dealing in years, then the effective interest rate per year had to be used.


that was calculated as follows:


the nominal interest rate per year is 12%.
the effective monthly interest rate per year is 1%.
the effective interest rate per year is (1.01)^12 = 1.12682503 -1 = .12682503 * 100 = 12.682503%.


ir equal to 12.682503 was entered as input to the problem as shown in the first display.


note that yearly payments were made at the beginning of each year.