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KCET2021MathematicsProbability

Given that, A and B are two events such that P(B)= 3 5 , P ( A B )= 1 2 and P(A B)= 4 5 , then P(A) is equal to

Options

  1. A3 10
  2. B1 2
  3. C1 5
  4. D3 5

Correct answer

B. 1 2

Step-by-step solution

Given, P(B)= 3 5 , P ( A B )= 1 2 and P(A B)= 4 5 P ( A B )= 1 2 P(A B) P(B) = 1 2 P(A B)= 1 2 3 5 = 3 10 Now, P(A B)= 4 5 P(A)+P(B)-P(A B)= 4 5 P(A)+ 3 5 - 3 10 = 4 5 P(A)= 4 5 + 3 10 - 3 5 = 8+3-6 10 = 5 10 P(A)= 1 2

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