JEE Main 2019 — Probability Question with Solution
From: JEE Main 2019 (Online) 8th April Evening Slot
Question
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 :
Choose an option
Show full solutionCorrect option: C
Correct answer
C4
Step-by-step explanation
Probablity of getting head P(H) =
Probablity of getting tail P(T) = 1 - =
Probability of observing at least one head out of n tosses
= 1 - Probability of observing no head occurs out of n tosses
= 1 -
According to the question,
1 -
As 23 = 8
24 = 16
Minimum value of n = 4
Probablity of getting tail P(T) = 1 - =
Probability of observing at least one head out of n tosses
= 1 - Probability of observing no head occurs out of n tosses
= 1 -
According to the question,
1 -
As 23 = 8
24 = 16
Minimum value of n = 4
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This is a previous-year question from JEE Main 2019, 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.