Answer:
[tex]\frac{1}{20}[/tex]
Step-by-step explanation:
To solve this problem, we can use the definition of probability: the amount of desirable outcomes divided by the total amount of outcomes. In order to find the probability of dependent events, events that depend on each other, we multiply the probability of the first event by the probability of the second event happening after the outcome of the first. Our two events are choosing a blue marble and then choosing a yellow.
There are a total of 16 marbles as given by the problem, this is our total number of outcomes. There are 4 outcomes where we can pick a blue marble, so the probability of choosing a blue marble is [tex]\frac{4}{16}[/tex] or [tex]\frac{1}{4}[/tex].
Now, we need to find the probability of choosing a yellow marble after the blue marble. If we already chose a blue marble, in total, there will only be 15 marbles instead of 16, because it is with out replacement. This gives us the total amount of outcomes. Next, we picked a blue already, so it does not affect the amount of yellow marbles left, which is 3 yellow marbles. From this, we can say the probability of picking a yellow marble given a blue marble was already picked is [tex]\frac{3}{15}[/tex] or [tex]\frac{1}{5}[/tex].
All we have to do now is multiply the two probabilities to find what we are looking for: [tex]\frac{1}{4} *\frac{1}{5} =\frac{1}{20}[/tex]. So, the probability of drawing a blue marble followed by a yellow marble is [tex]\frac{1}{20}[/tex]
