I thought BigInteger was disabled for this one

ok....

This kata shouldn't be 5kyu for c#, but we can't blame you for using the tools of c# if they're not forbidden. I rate this solution as best practice, but not clever.

Omg RLY?
I think its not what about kata was..........................

Wrong solution

lol! I use bool declaration in this solution. After I see your solution, I realized my bool isn't needed. and when I use bool, mean I put conditions (true A and true B). When that condition meet, I still got error at test6 because test6 has trick by putting a or b as null. Then I add 2 more conditions. Now I feel pissed when I know this solution doesn't need condition lmao!

Wrong solution

Finish the solution so that it returns the sum of all the multiples of 3 or 5 BELOW the number passed in.

and

Note: If the number is a multiple of both 3 and 5, ONLY COUNT IT ONCE.

3 + 5 + 6 + 9 + 10 + 12 + 15 + 18 = 78

The sample test has problem for number = 20.

It should equal 93 while it is 78 now!

Line.Tickets(new int[]{25, 25, 25, 25, 50, 50, 100})) correct is YES
this algoritm gives NO.

No skills with cash)))

I tried using declaration expressions but it was throwing errors... lol
But nice solution very elegant.

test [25, 25, 50, 50, 100] -> NO. this code return -> YES

Because C89

who mark it as clever !!?