JEE Main 2021 — Probability Question with Solution
From: JEE Main 2021 (Online) 25th July Evening Shift
Question
A fair coin is tossed n-times such that the probability of getting at least one head is at least 0.9. Then the minimum value of n is ______________.
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Show full solutionCorrect answer: 4
Correct answer
4
Step-by-step explanation
P(Head) =
1 P(All tail) 0.9
0.9
nmin = 4
1 P(All tail) 0.9
0.9
nmin = 4
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This is a previous-year question from JEE Main 2021, covering the Probability chapter of Mathematics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.