Question 970534
it depends upon the language and chance of outcome.

likely has different meanings.  It would be >50% legally, maybe >80%.
possible has many meanings, from extremely unlikely (still possible), to perhaps 25-50%.
Certain is 1.
impossible is 0.
unlikely is less than 50% in some circles or less than 10-25% in others.

These terms are vague and need to be clearly defined, with the exception of certain and impossible.

Only probability can be assigned a true number, and subjective probability is nothing more than a guess.