Suppose I have a fair coin and an unfair coin. The fair coin has head, tail, the unfair coin has both heads.
You pick one coin at random and toss them two times and observe the outcomes.
Which of the figure below is a better probability tree representation of these experiments (top or bottom)?
I am raising the question because, in the first figure, it seems to draw the head twice is redundant, given that the probability of getting a head is certainty.