Even through this has no impact for solution, but man this math is bad.
On description we have sum: 1041(that's ok), 1083.86 (but real sum is 1083,681) and 1128.30 (with real sum: 1128.111921). This is really confused me

Go Translation

C++ Translation.

Julia translation moved from duplicate kata String Breakers.

This kata is a subject to deduplication process here: https://github.com/codewars/content-issues/issues/196.
Please join the discussion to help us identify duplicate kata and retire them.

Maybe give the formulae as they require prior knowledge which has nothing to do with coding, or suggest people google as a legitimate coding skill.
Principal * interest rate = interest
interest * tax rate = tax
Principal + interest - tax = investment return
investment return is next year's principal

C#

• Method name should be PascalCase (Please refer to implementation of backward compatibility here )

• Actual and expected are swapped in fixed tests

This kata is very smart. I enjoy doing this...
But look at the example. Instead of 1083.86 for 2 years, it's 1083.681 (maths stuffs).
Check the calculation again.
Sincerly great kata for brain testing.

ngl description of kata is very unclear

For people who don't know how taxes work:
Tax is a part of INTEREST you pay to governmetn, not the part of ALL MONEY you have.
Hope this comment'll be helpful.

UPD
The formula is going to be like this: NP = P+(PI)-(PI*T)

Test case gave me an error. Removing ".pName" in getNamesTestExample() sorted that out. Also the description could be cleaned up slightly (you are mixing fname and First Name).