# Example 5 - Chapter 13 Class 12 Probability

Last updated at May 29, 2018 by Teachoo

Last updated at May 29, 2018 by Teachoo

Transcript

Example 5 (Introduction) A die is thrown 3 times S = {(1,1,1), (1,1,2), .........., (1,1,6), (1,2,1), (1,2,2), .........., (1,2,6), (1,3,1), (1,3,2), .........., (1,3,6), (1,4,1), (1,4,2), .........., (1,4,6), (1,5,1), (1,5,2), .........., (1,5,6), (1,6,1), (1,6,2), .........., (1,6,6), (2,1,1), (2,1,2), .........., (2,1,6), (2,2,1), (2,2,2), .........., (2,2,6), (2,3,1), (2,3,2), .........., (2,3,6), (2,4,1), (2,4,2), .........., (2,4,6), (2,5,1), (2,5,2), .........., (2,5,6), (2,6,1), (2,6,2), .........., (2,6,6), (3,1,1), (3,1,2), .........., (3,1,6), (3,2,1),.........., (3,2,6), (3,3,1),.........., (3,3,6), (3,4,1),.........., (3,4,6), (3,5,1),.........., (3,5,6), (3,6,1),.........., (3,6,6), (4,1,1), ……………..(4,6,6), (5,1,1), ……………..(5,6,6), (6,1,1), ……………..(6,6,6), Example 5 A die is thrown three times. Events A and B are defined as below: A : 4 on the third throw B : 6 on the first and 5 on the second throw Find the probability of A given that B has already occurred. A die is thrown 3 times S = {(1,1,1),.........., (1,6,6), (2,1,1), .........., (2,6,6), (3,1,1), .........., (3,6,6), (4,1,1), ……………..(4,6,6), (5,1,1), ……………..(5,6,6), (6,1,1), ……………..(6,6,6), Given, A : 4 on the third throw B : 6 on the first & 5 on the second throw A ∩ B = {(6,5,4)} So, P(A ∩ B) = 1216 We need to find the probability of A, given that B has already occurred i.e. P(A|B) Now, P(A|B) = 𝑃(𝐴 ∩ 𝐵)𝑃(𝐵) = 1216 6216 = 16 ∴ P(A|B) = 𝟏𝟔

Examples

Example 1

Example 2

Example 3

Example 4

Example 5 You are here

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

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.