Chapter 13 Class 12 Probability



Slide45.JPG Slide46.JPG

Learn in your speed, with individual attention - Teachoo Maths 1-on-1 Class


Ex 13.1, 12 Assume that each born child is equally likely to be a boy or a girl. If a family has two children, what is the conditional probability that both are girls given that (ii) at least one is a girl? S = {(g, g), (g, b), (b, g), (b, b)} We need to find the probability that the children are girls, given that at least one is a girl. E : both the children are girls F : at least one child is a girl E = {(g, g)} P(E) = 1/4 F = {(g, g), (g, b), (b, g)} P(F) = 3/4 Also, E ∩ F = {(g, g)} So, P(E ∩ F) = 1/4 Now, P(E|F) = (𝑃(𝐸 ∩ 𝐹))/(𝑃(𝐹)) = (1/4)/(3/4) = 1/4 × 4/3 = 𝟏/𝟑

Ask a doubt
Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 13 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.