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AP EAMCET202021 Sep 2020Morning ShiftMathematicsProbabilityActual

If the probability for (A ) to fail in an exam is 0.2 and that for (B ) is 0.3, then the probability that either (A ) or (B ) fails is ( . ).

Options

  1. A0.2
  2. B0.4
  3. C0.5
  4. D0.3

Correct answer

C. 0.5

Step-by-step solution

Let, (P(A) ) is the probability for (A ) to fail in an exam and (P(B) ) is the probability for (B ) to fail in an exam. ( ) The probability that either (A ) or (B ) fails is ( array cc & P(A B)=P(A)+P(B)-P(A B) & P(A B) P(A)+P(B) & P(A B) 0.2+0.3 & P(A)=0.2 and P(B)=0.3 given & P(A B) 0.5 array ) Hence, option (c) is correct.

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