I have fixed the interest and amount variable. I didn't want to use P and n because some people might not know what they mean,
although I will admit, my naming of variables isn't great lol

I was unaware of this being a duplicate. I just recently got the ability to make a kata
so I was just trying to make a simple kata that I knew I could make in short time. Thank you for letting me know,
I will be sure to keep that in mind when making more in the future.

Thank you for mentioning this. I have fixed the calculation. Please, if you find anything else, let me know and i'll do my best to fix the issues.

Ah, yes, so sorry about that. I forgot to change it in the sample tests aswell. Also i'll look into the approximately.

Thank you for the information, this is the first kata i have attempted to make. I fixed most your stated issues, although I do not know how to do approx equals, or how to check with a random test. I will continue to work and resolve as many issues that I can.