Subscribe to our Youtube Channel - https://you.tube/teachoo

Last updated at Feb. 11, 2020 by Teachoo

Transcript

Example 17 In a relay race there are five teams A, B, C, D and E. (a) What is the probability that A, B and C finish first, second and third, respectively. 3 teams will win from 5 teams Hence Total number of orders = 5P3 = 5!/(5 − 3)! = 5!/2! = (5 × 4 × 3 × 2!)/2! = 60 So, n(S) = 60 Let L be the event that A, B & C finish first second & third respectively Hence , L = {ABC} So, n(L) = 1 So, P(L) = (𝑛(𝐿))/(𝑛(𝑆)) = 𝟏/𝟔𝟎 Example 17 In a relay race there are five teams A, B, C, D and E. (b) What is the probability that A, B and C are first three to finish (in any order) (Assume that all finishing orders are equally likely) Let M be the event that A, B and C are first three in any order M = {ABC, ACB, BAC, BCA, CAB, CBA} Hence n(M) = 6 P(M) = (𝑛(𝑀))/(𝑛(𝑆)) = 6/60 = 𝟏/𝟏𝟎

Examples

Example 1

Example 2 Important

Example 3

Example 4 Important

Example 5 Important

Example, 6

Example 7

Example, 8 Important

Example 9 Important

Example 10 Important

Example, 11

Example 12 Important

Example 13 Important

Example 14 Important

Example 15 Important

Example 16

Example 17 Important You are here

About the Author

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.