Also, this would be a duplicate to many existing elementary DP (more specifically, coin change) katas, with a slight twist at the end.

Issues from the "harder" version of this kata also applies to this kata:

Tests are unacceptable: the description says

You are a baker that works in multiple stores, each store has a diferent number of oven types, some have ovens with 10 trays, others with just 4 trays, others with ovens with 4 trays and 10 trays (there are ovens with 1 tray up to 30).

but the actual tests only contains at most 2 trays, which becomes a much easier problem.

Also, this would be a duplicate to many existing elementary DP (more specifically, coin change) katas, with a slight twist at the end.

Anyways, even the tests are unacceptable: the description says

You are a baker that works in multiple stores, each store has a diferent number of oven types, some have ovens with 10 trays, others with just 4 trays, others with ovens with 4 trays and 10 trays (there are ovens with 1 tray up to 30).

but the actual tests only contains at most 2 trays, which becomes a much easier problem.

Similarly, random tests is a complete joke: It only tests [4, 10] against a multiple of 10, which has a trivial solution.

There is a dick move: random tests are secretly testing runtime each run and asserts that it does not exceed a certain value, with no indication this is being tested:

Test Failed
  Expected: less than or equal to 20
  But was:  75

This kata needs random tests.

the idea is that since there is nothing else, you cant tell if its a - or a . (because you have nothing to compare to) so by default you need to assume its a .

https://www.codewars.com/kata/5300901726d12b80e8000498

Yours is actually a simpler version of FizzBuzz (so the dificulty should be ajusted)

(btw you can search for keywords in the kata pages to look for puzzles that might be similar to yours or to find more FizzBuzz puzzles)

It's just a simple recursion

btw what algorithm is your brute force solution based? (it performs really really well compared with my brute force solution for the previous kata, mine took minutes yours takes 100ms to solve for 1000 trays)

added

Needs Random Tests.

so that generationg all possibilities is not possible

Tests should be revamped to prevent brute force solutions directly copied from the last one