Probability is the likeliness of something occurring.
For example: there are 10 marbles in a bag. 5 are blue and the other 5 are red. What are the chances of drawing a blue marble. You have a 50% chance of drawing a blue marble. Because half of them out of the ten are blue.
Okay certain and impossible events are exactly how they sound.
An impossible event can be something like an alien will invade the neighborhood houses at midnight. That’s impossible.
A certain event can be like: Sarah has school everyday this week. That kid a likely/ certain event that will happen.
I really hope I completely answered your question! Have a great afternoon...
~Brooke❤️