# Example 26 - Chapter 13 Class 12 Probability (Term 2)

Last updated at Feb. 15, 2020 by Teachoo

Last updated at Feb. 15, 2020 by Teachoo

Transcript

Example 26 Let X denote the number of hours you study during a randomly selected school day. The probability that X can take the values x, has the following form, where k is some unknown constant. P(X = x) = {โ(0.1 , ๐๐ ๐ฅ=0@๐๐ฅ, ๐๐ ๐ฅ=1 ๐๐ 2@๐(5โ๐ฅ), ๐๐ ๐ฅ=3 ๐๐ 4@0, ๐๐กโ๐๐๐ค๐๐ ๐)โค (a) Find the value of kMaking in tabular foArmat Since X is a random variable , its Sum of Probabilities is equal to 1 โ_0^4โใ๐(๐)ใ = 1 P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) = 1 0.1 + k + 2k + 2k + k = 1 6k = 1 โ 0.1 6k = 0.9 k = (0. 9)/6 k = 0.15 Example 26 (b) What is the probability that you study atleast two hours? Exactly two hours? At most 2 HoursOur probability distribution table is P(you study atleast two hours) = P(X โฅ 2) = P(X = 2) + P(X = 3) + P(X = 4) = 2k + 2k + k = 5k = 5 ร 0.15 = 0.75 P(you study exactly two hours) = P(X = 2) = 2k = 2 ร 0.15 = 0.30 P(you study atmost two hours) = P(X โค 2) = P(X = 0) + P(X = 1) + P(X = 2) = 0.1 + k + 2k = 0.1 + 3k = 0.1 + 3 ร 0.15 = 0.1 + 0.45 = 0.55

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Example 27 Deleted for CBSE Board 2022 Exams

Example 28 Important Deleted for CBSE Board 2022 Exams

Example 29 Important Deleted for CBSE Board 2022 Exams

Example 30 Important Deleted for CBSE Board 2022 Exams

Example 31 Important Deleted for CBSE Board 2022 Exams

Example 32 Important Deleted for CBSE Board 2022 Exams

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Example 34 Deleted for CBSE Board 2022 Exams

Example 35 Deleted for CBSE Board 2022 Exams

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Chapter 13 Class 12 Probability (Term 2)

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About the Author

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 10 years. He provides courses for Maths and Science at Teachoo.