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JEE Main20209 Jan 2020Evening ShiftMathematicsProbabilityActual

A random variable X has the following probability distribution: X : 1 2 3 4 5 P X : k 2 2 k k 2 k 5 k 2 Then, P X > 2 is equal to:

Options

  1. A7 12
  2. B1 36
  3. C1 6
  4. D23 36

Correct answer

D. 23 36

Step-by-step solution

W e know ∑ P i = 1 ⇒ 6 k 2 + 5 k = 1 6 k 2 + 5 k - 1 = 0 6 k 2 + 6 k - k - 1 = 0 6 k - 1 k + 1 = 0 ⇒ k = - 1 (rejected) ; k = 1 6 P X > 2 = k + 2 k + 5 k 2 = 1 6 + 2 6 + 5 36 = 6 + 12 + 5 36 = 23 36

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