Example 8 - Chapter 13 Class 12 Probability
Last updated at Feb. 15, 2020 by Teachoo
Transcript
Example 8 An urn contains 10 black and 5 white balls. Two balls are drawn from the urn one after the other without replacement. What is the probability that both drawn balls are black? We need to find probability that both balls drawn out are black Now, Probability both balls drawn are black = Probability first ball drawn is black × Probability second ball is black if first is black Finding both probabilities separately Probability first ball drawn is black There are 10 blacks balls out of 15 So, Probability = 10/15 = 2/3 Probability second ball drawn is black if first ball was black If first ball drawn was black, we are left with 9 black, 5 white balls So, Probability = (𝑅𝑒𝑚𝑎𝑖𝑛𝑖𝑛𝑔 𝐵𝑙𝑎𝑐𝑘 𝑏𝑎𝑙𝑙)/(𝑅𝑒𝑚𝑎𝑖𝑛𝑖𝑛𝑔 𝑏𝑎𝑙𝑙𝑠) = 9/14 Therefore, Probability both balls drawn are black = Probability first ball drawn is black × Probability second ball is black if first is black = 2/3 × 9/14 = 𝟑/𝟕
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Example 8 You are here
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Example 16
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Example 20 Important
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Example 22
Example 23
Example 24 Important
Example 25 Important
Example 26 Important
Example 27 Deleted for CBSE Board 2021 Exams only
Example 28 Important Deleted for CBSE Board 2021 Exams only
Example 29 Important Deleted for CBSE Board 2021 Exams only
Example 30 Important Deleted for CBSE Board 2021 Exams only
Example 31 Important Deleted for CBSE Board 2021 Exams only
Example 32 Important Deleted for CBSE Board 2021 Exams only
Example 33 Important
Example 34 Important Deleted for CBSE Board 2021 Exams only
Example 35 Important
Example 36 Important
Example 37 Important
Chapter 13 Class 12 Probability
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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.