WHAT IS PROBABILITY!? Probability means a chance of an even occurring like this.
Flipping a coin. 2 possibilities, heads or tails.
It's favourable over possible.
Favourable means the event you expect to happen and possible is that it could happen too but you don't expect it. Let's say you call heads when you flip a coin and it lands on tails, heads is what you want to happen but tails was a possible outcome also. so if you called heads the fraction would be 1/2 same thing with tails.
So I hope you learn more about probability.
Here's a video on Probability.
Also, here's a picture on Probability