9514 1404 393
Answer:
outcomes (top to bottom): SS, SG, GS, GG
all probabilities are 0.25
Step-by-step explanation:
Each outcome is identified by the labels on the ends of the corresponding tree branch, in order left-to-right. The top one is SS, for example, and the next one down is SG. Continuing down the tree, the outcomes are GS and GG.
Each letter has a probability of 1/2, so any pair of letters will have a probability of (1/2)(1/2) = 1/4 = 0.25.
__
This method of identifying outcomes and their probabilities can ensure that you find all outcomes. The sum of probabilities should be 1.00 if the tree is properly constructed.