I had this same issue in Python. This test is the issue: Test.assert_equals(race(820, 850, 550), [18, 20, 0]) My math (same as above math) calculates 59.99999999999574 seconds, which if stored with less precision would return 60 if converted to int. I think that test should just be removed or altered slightly so as to not produce an amount of seconds so close to 60.

hmmm... although im not so sure, but it could be due to rounding errors. why dont you try convert the velocity from feets/hours to feets/seconds and try it again,it may give more accurate results.

I had a similar problem on the python kata ...

it is a float precision problem - if you print your values, you will see.
In my opinion the test cases are not well selected for "the fractions of a second won't matter" description

tough one...

563 guys passed the JS kata so it is not an error of the kata.
Post a question about your code, not an issue.