(i)[2]
Draw a complete labelled tree diagram for this information.
(ii)[4]
Given that Megan does not get an immediate reply to a message, find the probability that the message was an email.
Mathematics 9709 · AS & A Level · The Poisson distribution
The Poisson distribution — practice question
Megan communicates with her friends in one of $3$ possible ways: text, email or social media. For each message, the chance that she uses text is $0.3$ and the chance that she uses email is $0.2$. She gets an immediate reply to a text message with probability $0.4$, to an email with probability $0.15$ and to social media with probability $0.6$.
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