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Question
Two coins are tossed once. Find P (A/B) in each of the following:
A = Tail appears on one coin, B = One coin shows head.
Solution
Consider the given events.
A = Tail appears on one coin
B = One coin shows head
Clearly,
A = {(H, T), (T, H)}
B = {(H, T), (T, H)}
\[\text{ Now } , \]
\[A \cap B = \left\{ \left( H, T \right), \left( T, H \right) \right\}\]
\[ \therefore \text{ Required probability } = P\left( A/B \right) = \frac{n\left( A \cap B \right)}{n\left( B \right)} = \frac{2}{2} = 1\]
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