probability of event
Intro:
drawing. Assuming that the square area is 1, then the value of P(A) is the probability that the point falls on A.
We can find many probabilities by drawing graphs.
Such as: P(AB)=0.25,
P(BA)=0.23,
P(A+B)=0.58;
some concepts:
Example 1:
Solution:
0.3.
Just draw a picture.
Example 2:
Solution:
5/12.
Some additions:
independence of events
The stem of the question looks like this, which tells us that the events are independent of each other , or that the probability of two events occurring is the product of their respective occurrences .
Independence related knowledge:
Example 1:
Solution:
0.2.
Draw graphs + solve equations.
Example 2:
Solution:
2/3.
Draw graphs + solve equations .
Don't feel it intuitively, it will feel that the answer is 4/9, which is obviously wrong.
