# Ex 13.1, 7 - Chapter 13 Class 12 Probability

Last updated at May 29, 2018 by Teachoo

Last updated at May 29, 2018 by Teachoo

Transcript

Ex 13.1, 7 Two coins are tossed once, where (i) E : tail appears on one coin, F : one coin shows head Two coins are tossed once Let heads be denoted by ‘h’ & tails be denoted by ‘t’ S = {(h, h), (h, t), (t, h), (t, t)} We need to find the probability that tail appears on one coin, if we know that one coin shows head Let F: one coin shows head E : tail appears on one coin We need to find P(E|F) Also, E ∩ F = {(h, t), (t, h)} P(E ∩ F ) = 24= 12 Now, P(E|F) = 𝑃(𝐸 ∩ 𝐹)𝑃(𝐹) = 12 12 = 1 Ex 13.1, 7 Two coins are tossed once, where (ii) E : no tail appears, F : no head appears S = {(h, h), (h, t), (t, h), (t, t)} We need to find the probability that no tail appears, if known that no head appears F: no head appears E: no tail appears We need to find P(E|F) Also, E ∩ F = ϕ So, P(E ∩ F ) = 0 Now, P(E|F) = 𝑃(𝐸 ∩ 𝐹)𝑃(𝐹) = 0 14 = 0 ∴ P(E|F) = 0

Chapter 13 Class 12 Probability

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