Mathematics

Question

In the final exams, 40% of the students failed chemistry, 25% failed physics, and 19% failed both chemistry and physics. What is the probability that a randomly selected student failed physics given that he passed chemistry?

I have answered the question in the image below, but I would like to know if it is correct. If it is not, please include an explanation of why, as well as the step by step to get the correct answer
In the final exams, 40% of the students failed chemistry, 25% failed physics, and 19% failed both chemistry and physics. What is the probability that a randomly

1 Answer

  • Answer:

      10%

    Step-by-step explanation:

    If 40% failed chemistry then 60% passed chemistry.

    If 19% failed both chemistry and physics, and 25% failed physics, then 6% passed chemistry and failed physics.

    If we let p' represent failing physics and c represent passing chemistry, then ...

      P(p'|c) = P(p'c)/P(c)

      P(p'|c) = 6%/60% = 0.10 = 10%

    If the randomly chosen student passed chemistry, the probability is 10% that he failed physics.

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    Your answer is correct.

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