At first, the probability of choosing a black ribbon is 8/20, but if one is chosen, then the probability of choosing a black ribbon would be 7/19, since we are substracting one ribbon from the sample space, therefore, using the product rule, we have:
[tex]\frac{8}{20}*\frac{7}{19}=\frac{56}{380}=\frac{14}{95}[/tex]
therefore, the probability i s 14/95
