JEE Mains · Maths · STD 12 - 13. probability
The minimum number of times one has to toss a fair coin so that the probability; of observing at least one head is at least \(90\%\) is
- A \(2\)
- B \(3\)
- C \(4\)
- D \(5\)
Answer & Solution
Correct Answer
(C) \(4\)
Step-by-step Solution
Detailed explanation
\(1-\frac{1}{2^{n}}>\frac{9}{10}\) \(\Rightarrow \frac{1}{10}>\frac{1}{2^{n}}\) \(\Rightarrow 2^{n}>10\) \(\Rightarrow n=4\)
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