Ex 13.2, 12 - A die is tossed thrice. Find probability of odd - Ex 13.2

Slide30.JPG
Slide31.JPG

  1. Chapter 13 Class 12 Probability
  2. Serial order wise
Ask Download

Transcript

Ex 13.2, 12 A die is tossed thrice. Find the Probability of getting an odd number at least once. A die is tossed thrice Probability of getting an odd number at least once = Probability of getting an odd number once + Probability of getting an odd number twice + Probability of getting an odd number thrice = 1 – Probability of getting an odd number 0 times = 1 – Probability of getting an even number all 3 times Let the events be O : getting an odd number E : getting an even number Now, Required Probability = 1 – P(EEE) So, P(EEE) = P(E) × P(E|E) × P(EE|E) P(E) = Probability of getting an even number Even numbers on a die = {2, 4, 6} = 3 Total numbers on a die = {1, 2, ……, 6} = 6 ∴ P(E) = 3﷮6﷯ = 1﷮2﷯ P(E|E) = Probability of getting an even number on the second die given even number appeared on the first die Even numbers on a die = {2, 4, 6} = 3 Total numbers on a die = {1, 2, ……, 6} = 6 ∴ P(E|E) = 3﷮6﷯ = 1﷮2﷯ P(EE|E) = Probability of getting an even number on the third die, given even numbers appeared on the first two die. Even numbers on a die = {2, 4, 6} = 3 Total numbers on a die = {1, 2, ……, 6} = 6 ∴ P(EE|E) = 3﷮6﷯ = 1﷮2﷯ So, P(EEE) = P(E) × P(E|E) × P(EE|E) P(EEE) = 1﷮2﷯ × 1﷮2﷯ × 1﷮2﷯ = 1﷮8﷯ ∴ Probability of getting an odd number at least once = 1 – P(EEE) = 1 – 1﷮8﷯ = 𝟕﷮𝟖﷯

About the Author

Davneet Singh's photo - Teacher, Computer Engineer, Marketer
Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 7 years. He provides courses for Mathematics and Science from Class 6 to 12. You can learn personally from here https://www.teachoo.com/premium/maths-and-science-classes/.
Jail