# Ex 13.1, 15 - Chapter 13 Class 12 Probability (Term 2)

Last updated at Feb. 15, 2020 by

Last updated at Feb. 15, 2020 by

Transcript

Ex 13.1, 15 Consider the experiment of throwing a die, if a multiple of 3 comes up, throw the die again and if any other number comes, toss a coin. Find the conditional probability of the event ‘the coin shows a tail’, given that ‘at least one die shows a 3’.A die is thrown If multiple of 3 comes up, the die is thrown again If any other number comes up, a coin is tossed Thus, our event looks like We need to find the Probability of the coin showing a tail, given that at least one die shows a 3. E : coin shows a tail F : at least one die shows 3 We need to find P(E|F) E = { (1, T), (2, T), (4, T), (5, T)} P(E) = P(1, T) + P(2, T) + P(4, T) + P(5, T) = 1/12+1/12+1/12+1/12 = 4/12 = 𝟏/𝟑 F = { (3, 1), (3, 2), (3, 3), (3, 4), (3, 5), (3, 6), (6, 3)} P(F) = P(3, 1) + P(3,2 ) + ... + P(3,6) + P(6, 3) = 1/36+1/36+1/36+1/36+1/36+1/36+1/36 = 𝟕/𝟑𝟔 Also, "E"∩"F" = ϕ So, P("E" ∩"F" )=0 Now, P(E|F) = 𝑃(𝐸 ∩ 𝐹)/(𝑃(𝐹)) = 0/(7/36) = 0

Ex 13.1

Ex 13.1, 1

Ex 13.1, 2

Ex 13.1, 3 Important

Ex 13.1, 4

Ex 13.1, 5

Ex 13.1, 6 (i)

Ex 13.1, 6 (ii) Important

Ex 13.1, 6 (iii)

Ex 13.1, 7 (i)

Ex 13.1, 7 (ii)

Ex 13.1, 8

Ex 13.1, 9

Ex 13.1, 10 (a) Important

Ex 13.1, 10 (b) Important

Ex 13.1, 11

Ex 13.1, 12 Important

Ex 13.1, 13 Important

Ex 13.1, 14

Ex 13.1, 15 You are here

Ex 13.1, 16 (MCQ) Important

Ex 13.1, 17 (MCQ) Important

Chapter 13 Class 12 Probability (Term 2)

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 10 years. He provides courses for Maths and Science at Teachoo.