a) Since we have seven possible outcomes and for each performer we have that the probability to perform first is 1/7, therefore, the probability that C will perform first is 1/7
b) For the probability that F or G will perform first, we have to add both probabilities to get the following:
[tex]\frac{1}{7}+\frac{1}{7}=\frac{2}{7}[/tex]therefore, the probability that F or G will perform first is 2/7
