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Three Coins Are Tossed Together. Find the Probability of Getting:(Ii) at Least Two Heads

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Question

Three coins are tossed together. Find the probability of getting at least 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 E2 = event of getting at least two heads
Then E2 = {HHH, HHT, HTH, THH}
i.e. (E2) = 4

\[\therefore P\left( E_2 \right) = \frac{n\left( E_2 \right)}{n\left( S \right)} = \frac{4}{8} = \frac{1}{2}\]

 

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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 4.2 | Page 46

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