(a)[3]
Find the probability that Seva selects at least one red marble.
(b)[2]
Find the probability that Seva obtains a head given that he selects no red marbles.
Mathematics 9709 · AS & A Level · Probability
Probability — practice question
Seva owns a coin that is biased so that, whenever it is tossed, the chance of getting a head is $\frac{1}{3}$. He also has a bag with $4$ red marbles and $5$ blue marbles. Seva throws the coin. If a head is obtained, he chooses one marble from the bag at random. If a tail is obtained, he chooses two marbles from the bag at random without replacement.
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