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Q: Maheshwari wants to buy 7 floors in an 68 storied building whose numbering stars from 1 upto 68. But she has to follow certain rules which are as follows : 1) None of the floor should be a prime number 2) None of the digit of the floor should be a prime number 3) Maheshwari cannot buy the 1st floor as it is being assigned to the architect. So how many options are left with Maheshwari to buy the floors ?

  • 1
    11
  • 2
    17
  • 3
    13
  • 4
    19
  • Show Answer
  • Workspace

Answer : 2. "17"
Explanation :

Answer: B) 17 Explanation: Since floor starts form the 1 therefore 2 will be the 1st floor.Form 1 to 10 only 4,6,8,9,10 are not prime.Form 11 to 20 only 14 ,16,18 are not prime also non of their digits are prime.From 21 to 30 each number has a prime number so it must no be consider.In between 40 to 49 we have to consider only 40,44,46,48,49.50 to 59 follow either of the condition so we have too neglect it.In between 60 to 68 60,64,66,68.total option = 17.

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