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GATE 2018 ME (ME1) – Question 28

Engineering Mathematics · Probability and Statistics: Probability, conditional probability, sampling theorems · 1 mark · Multiple choice

A fair six-faced die is rolled five times. Probability, in percent, of obtaining ONE at least four times is ______.

  1. 33.3
  2. 3.33
  3. 0.33
  4. 0.0033

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Correct answer: (C) 0.33

Explanation

For binomial X with n = 5 and p = 1/6, $$P(X\ge4)=\binom54(1/6)^4(5/6)+(1/6)^5=26/7776.$$ Multiply by 100: 0.334%, approximately 0.33% (C).