InterviewSolution
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In a town of 6000 people, 1200 are over 50 years old, and 2000 are females. It is known that 30% of the females are over 50 years. What is the probability that a randomly chosen individual from the town is either female or over 50 years? |
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Answer» let A denote the event that the chosen individual is female and B denote the event that the chosen individual is over 50 years old. Given : Town consists of 6000 people, 1200 are over 50 years old, and 2000 are females To find : Probability that a randomly chosen individual from the town is either female or over 50 years = P(A or B) The formula used : Probability = = \(\frac{favourable\,number\,of\,outcomes}{Total\,no.of\,outcomes}\) P(A or B) = P(A) + P(B) - P(A and B) For the event A , There are 2000 females present in a town of 6000 people Favourable number of outcomes = 2000 Total number of outcomes = 6000 P(A) = \(\frac{2000}{6000}\) = \(\frac{1}{3}\) For the event B, There are 1200 are over 50 years of age in a town of 6000 people Favourable number of outcomes = 1200 Total number of outcomes = 6000 P(A) = \(\frac{2000}{6000}\) = \(\frac{1}{5}\) 30% of the females are over 50 years For the event A and B, \(\frac{30}{100}\times2000 = 600\) females are over 50 Favourable number of outcomes = 600 P(A and B) = \(\frac{600}{6000}\) = \(\frac{1}{10}\) = P(A or B) = P(A) + P(B) - P(A and B) P(A or B) = \(\frac{1}{3}+\frac{1}{5}+\frac{1}{10}\) P(A or B) = \(\frac{10+6-3}{30}\) = \(\frac{13}{30}\) P(A or B) = \(\frac{13}{30}\) The probability that a randomly chosen individual from the town is either female or over 50 years = P(A or B) = \(\frac{13}{30}\) |
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