Example 21 - Class 12
Last updated at March 11, 2017 by Teachoo
Transcript
Example 21 A man is known to speak truth 3 out of 4 times. He throws a die and reports that it is a six. Find the probability that it is actually a six. Let S1 : man speaks the truth S2 : man lies E : six on the die We need to find the Probability that it is actually a six, if the man reports that it a six i.e. P(S1|E) P(S1|E) = 𝑃 𝑆1.𝑃(𝐸| 𝑆1)𝑃 𝑆1.𝑃(𝐸| 𝑆1)+𝑃 𝑆2.𝑃(𝐸| 𝑆2) Putting value in formula, P(S1|E) = P(S1) . P(E|S1) P(S1) . P(E|S1) + P(S2) . P(E|S2) = 34 × 16 34 × 16 + 14 × 56 = 14 × 16 × 3 14 × 16 3 + 5 = 38 Therefore, required probability is 𝟑𝟖
Examples
Example 1
Example 2
Example 3
Example 4
Example 5
Example 6 Important
Example 7 Important
Example 8
Example 9
Example 10
Example 11 Important
Example 12
Example 13
Example 14
Example 15
Example 16
Example 17 Important
Example 18 Important
Example 19
Example 20 Important
Example 21 Important You are here
Example 22
Example 23
Example 24
Example 25 Important
Example 26 Important
Example 27 Important
Example 28 Important
Example 29 Important
Example 30
Example 31 Important
Example 32 Important
Example 33
Example 34
Example 35 Important
Example 36 Important
Example 37
Chapter 13 Class 12 Probability
Serial order wise
About the Author
Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 8 years. He provides courses for Maths and Science at Teachoo. You can check his NCERT Solutions from Class 6 to 12.