probability problems

Probability Problems

Tutorial on ProbabilityClass 9

QuizQuestion 1: A coin is tossed 1000 times; we get 499 times head and 501 times1) What is the empirical probability of getting head ?2) What is the empirical probability of getting tail?3) Does the sum of above two probability equals 1?

SolutionTotal number of trials =1000No of trails which head came =499So No of trails where tail came=1000-499=501a)Now Empirical probability of getting

head=(No of trails which heads came)/(Total Number of trials)empirical probability of getting head=499/1000So empirical or experimental probability of getting head P(H) is calculated as=.499

Solutionb) empirical probability of getting tail =(No of trails which tails came)/(Total Number of trials)Sp empirical probability of getting head=501/1000So empirical or experimental probability of getting head P(T) is calculated as=.501

c) Now P(H) +P(T)= .499+.501=1

Question-2 In a cricket match, a batswoman hits a boundary 6 times out of 30 balls she plays. Find the probability that she did not hit a boundary.Solution:Let P is the event of hitting the boundaryn(P)=6Let Q be the event of not hitting the boundaryn(Q)= 30- n(P)=24Probability of not hitting the boundary=   n(Q)/30= 24/30=4/5

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