Just solved it. Not broken.

This kata is still messing with people's head :)

Yeah, that was painful.

I'm sorry too! You are right but it is not the question. No number x gives exactly m=6540715897 for n=48 hence the answer -1. Am I clear enough?-)

I think you don't have correctly understood the kata. The description says:

In other words we must find x such as n choose x = m (1) for a given m and a given n

You have to solve an equation not an inequation. 37 choose 11 gives 854992152, not 6540715897

Same problem here. :/

Thanks for letting us know. This has been fixed. You totally deserve the extra 2 honor for reporting this :)

Fixed, now. I just forgot to copy over the numericalCompare function. Sorry about that. ;/

That's a known problem. Code from the "preloaded" section doesn't get preloaded on example test case runs, but they will work on submit. One can use the following variant of 'numericalCompare` to check the code before submitting:

var numericalCompare = function(a,b){
  return +a - +b;
}