I totally agree with Matteo. The only reason why I wasted my time with this problem is to be able to properly complain about such a loss of time.
It is not about English not being your mother tongue though. English is not my mother tongue neither and I can give complete and non contradictory instructions.
The instructions doesn't specify why the value of the old car matters (you have to understand from the examples you can sell it in order to buy the new one). The explanation about the float rounding is contradictory. It tells you to truncate and to aproximate it to the nearest int in the same phrase. It is a disaster.

I improved the Kotlin assertion messages. The problem should be clearer now.

Interpreting instructions in a real-world application is not always easy either. I like to think of these as practice for dense or unclear legacy code or hard to read documentation. It is also often the case that the author's first language is not English, in which case I'm sure a suggestion for clearer instruction would be helpful

Without leading zeros. k is 2 for d=3.

old kata, other ranking scale as nowadays, yada yada yada .. enjoy the easy points !

Reraised as issue. You can refer sample tests for more clarity tho

Grave18 You could still minimize it with an inline || operator , just saying =)

or are you talking about aosphyma's response?

I don't see how. Where will it match letters?

Massive eye-roll to Hmekus.

Imagine thinking going above-and-beyond meant someone had to have cheated because surely they wouldn't have the knowledge to make a more complete solution.

I think, he just copied the solution from the internet:)
Its not good if you want to improve your skills.