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Three Coins Are Tossed Together. Find the Probability of Getting:(I) Exactly Two Heads

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Question

Three coins are tossed together. Find the probability of getting exactly two heads

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Solution

When three coins are tossed once, the sample space is given by
S = {HHH, HHT, HTH, HTT, THH, THT, TTH, TTT}
i.e. (S) = 8

 Let E1 = event of getting exactly two heads
Then E1 = {HHT, HTH, THH}
i.e. n(E1) = 3

\[\therefore P\left( E_1 \right) = \frac{n\left( E_1 \right)}{n\left( S \right)} = \frac{3}{8}\]

 

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Concept of Probability - Probability of 'Not', 'And' and 'Or' Events
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Chapter 33: Probability - Exercise 33.3 [Page 46]

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R.D. Sharma Mathematics [English] Class 11
Chapter 33 Probability
Exercise 33.3 | Q 4.1 | Page 46

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