In order to give a representation of the formula:
P(A or B)=P(A)+P(B)-P(A and B)
I just created the following figure:
So, here P(green or square)=6/11
But when calculated with the formula P(green)+P(square)-P(green AND square)=(5+6-2)/11=9/11
One problem is that the events green and square are not independent (there are more green square than green circles)
Am I right to say that the formula only work when the events are independent, and that my problem here is precisely that or is it that I do something wrong in my calculations?
P(A or B)=P(A)+P(B)-P(A and B)
I just created the following figure:
So, here P(green or square)=6/11
But when calculated with the formula P(green)+P(square)-P(green AND square)=(5+6-2)/11=9/11
One problem is that the events green and square are not independent (there are more green square than green circles)
Am I right to say that the formula only work when the events are independent, and that my problem here is precisely that or is it that I do something wrong in my calculations?