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Thomas wants to invite Madeline to a party. He has 80% chance of bumping into her at school. Otherwise, he'll call her on the phone. If he talks to her at school, he's 90% likely to ask her to the party. What is the probability of Thomas inviting Madeline to the party over the phone?

Thomas wants to invite Madeline to a party. He has 80% chance of bumping into her-example-1
User SandaliTP
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1 Answer

16 votes
16 votes

Recall that the probability must add 1, therefore:


0.6+x=1

Solving for x, we get:


\begin{gathered} x=1-0.6 \\ x=0.4 \end{gathered}

Therefore, the probability of Thomas inviting Madeline to the party over the phone is:


0.2\cdot0.4=0.08

or 8%.

User Garrett McCullough
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