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COMEDK2023MathematicsProbability

If a number n is chosen at random from the set 11,12,13, , 30 . Then, the probability that n is neither divisible by 3 nor divisible by 5 , is

Options

  1. A7 20
  2. B9 20
  3. C11 20
  4. D13 20

Correct answer

C. 11 20

Step-by-step solution

Here, number which are divisible by either 3 or 5 are 12,15,18,20,21,24,27,30 . Total numbers =9P( number either divisible by 3 or 5 )= 9 20 P (number neither divisible by 3 nor 5 ) =1-P (number either divisible by 3 or 5 ) =1- 9 20 = 11 20

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