IBM Ponder This: November Edition

Replies

• 

  durga ch

  is it 3?
  
  
  is number divisible by 2
  a. Y - 8,4,6,2 ( any number which is a multiple of these numbers will have least divisor as 2)
  answer = 2
  b. N- 3,5,7,9 ( if not by two then they can have any of these numbers as divisors)
  b.1) is number divisible by 3
  Y - answer = 3
  b.2) is the number divisbile by 5
  Y - answer = 5
  N - answer = 7
  
  if none of above is correct, then number is prime so smallest number divisor apart from 1 is number it self.
• 

  durga ch

  addition:
  its 4
  
  after all the above questions : one more question as:
  is number divisible by 11 😀
  
  I asked my friend to suggest a number and she said 121! pop! it doesnot satify any of the above questions so yeah, its 4
• 

  Saandeep Sreerambatla

  Actually I didnt understand the question !!
  
  Durga, Can you explain it a bit clearly. 😔
• 

  durga ch

  ok.
  what i understood is this
  
  you choose a number x between 2 and 169.
  
  now I ask you n number of questions for which you answer yes or no and I have to deduce the minimum divisor what can divide the number based n your 'yes' or 'no'
  
  since we are talking about least divisor, i started with 2 and since any number divisible by 4,6,8 can be divided by 2 we dont peoceed further and decide that its divisible by 2.
  
  i f not divisible by 2 next number u proceed to consider is 3 , and any number which is divisible by 9 will be diviisble by 3 hence you rule out 9 as well.
  
  now left with 5,7 if the number is divisible by 5, then thats the minimum divisor aif not then 7
  
  hence i said in total 3 questison
  
  but later while i was testing it out, i realised that we have a prime number square as well which is 121 and hence fourth question was added.
  
  For exmaple consider number 49
  Q1: is number divisible by 2 - no
  Q2: is number divisible by 3 - no
  Q3: is the number divisible by 5 - no
  hence number is divisible by 7
  
  I am not sure if this is the answer, but this is what i deduced when i read the question.
  
  i