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99 Percentile Qs Bank for JEE MainMathematicsProbability

Let X ~ B n , p , if E X = 5 , V a r X = 2 . 5 then P X < 1 = …

Options

  1. A1 2 11
  2. B1 2 10
  3. C1 2 6
  4. D1 2 9

Correct answer

B. 1 2 10

Step-by-step solution

Here, E x = n P = 5 a n d V a r x = n p q = 2.5 ∴ q = 2.5 5 = 1 2 ∴ p = 1 2 a n d n = 10 Now, P x < 1 = P ( x = 0 ) ⇒ P x < 1 = 10 C 0 1 2 10 ⇒ P x < 1 = 1 2 10

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