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MHT CET202015 Oct 2020Morning ShiftMathematicsProbabilityActual

In a box containing 100 bulbs, 10 are defective. The probability that out of 20 bulbs selected at random, none is defective is

Options

  1. A10 ( 1 10 )²⁰
  2. B20 ( 9 10 )²⁰
  3. C5 ( 1 10 )²⁰
  4. D( 9 10 )²⁰

Correct answer

D. ( 9 10 )²⁰

Step-by-step solution

Let X denote number of defective bulbs out of 20 bulbs p = probability of getting defective bulb = 10 100 = 1 10 q =1- 1 10 = 9 10 and n =20 , Probability of getting no detective bulb is = ²⁰ C ₀ ( 9 10 )²⁰ ( 1 10 )⁰= ( 9 10 )²⁰

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