How do you master probability? (1 Viewer)

[Carrotsticks]

Hmm this is only happening in 2u probability but initially I was rote learning, as compared to now where I actually think about the question. Basically I'll get straight to the point:

1. Question asks me to find probability of getting x jelly beans from two packets.
2. I get confused whether to use addition or product rule.

That's it.

Addition for independent events (usually requires addition of 'cases')

ie: Probability of getting at most 2 distinct red marbles from a bag containing N marbles = P(no red) + P(1 red) + P(2 red) etc etc...

Product for dependent events (if we are doing this all in 1 action, you usually multiply the probability of each action)

ie: Probability of getting 2 distinct red marbles and then 2 distinct blue marbles = P(one red) x P(one red) x P(one blue) x P(one blue)