today I want to share a short notice on unions calculations in statistics by example of the following puzzle:
You are picking flowers from a garden. The garden contains flowers of varying colors, including flowers that are completely blue, flowers that are completely pink, and also flowers that are both colours. The probability of picking a flower that is at least partly blue is 0.4 and the probability of picking a flower that is at least partly pink is 0.2.
Question, how to calculate probability of picking flower that is blue, pink or both.
The answer is simple. First of all it's good to remember formula:
Now let's mark B as blue fragmnet, P as pink fragment.
And according to formula we have the following:
P(P or B) = 0.2 + 0.4 - 0.2*0.4