N is an integers and N>2 at most how many integers among N+2,N+4,N+5,N+6 and N+7 are prime integers?
a) 1 ,b)3 ,c)2, d)4

• 2....
  start with 3...we got 5,6,7,8,9
  we gust got 2 prime no among them.
  and it is true for any no. of n.
• 11 years agoHelpfull: Yes(34) No(3)
• Ans. (c) 2
  
  For N=3 we have - 5,7,8,9,10 so 2 prime
  For N=4 we have - 6,8,9,10,11 so 1 prime
  For N=5 we have - 7,9,10,11,12 so 2 prime
  For N=6 we have - 8,10,11,12,13 so 2 prime
  & so on....
  So max no of Primes are 2
  
• 11 years agoHelpfull: Yes(17) No(1)
• 2....
  start with 3...we got 5,7,8,9,10
  we gust got 2 prime no among them.
  and it is true for any no. of n.
  Here 5 and 7 prime integers.
• 11 years agoHelpfull: Yes(13) No(0)
• every prime no. follows the logic
  6N+1 or 6N-1.
  but this doesnt mean every no which follows this logic is prime.
  except 2,all prime no.s are odd.
  now,
  since N is an integer,so 6N will always be even. to make it odd we have to add an odd no to 6N.
  in our question we have only to set which can make odd(N+5 and N+7). so we can have max of two prime no.
  ans=c
• 11 years agoHelpfull: Yes(7) No(0)
• c)2..if let n=3
• 11 years agoHelpfull: Yes(3) No(8)
• if we solve this question by putting n as 3,4,5,6 n so on
  we got max 2 prime no each time as pattern flow with numbers
  if we put number from 3 we get
  For N=3 we have - 5,7,8,9,10 so 2 prime
  For N=4 we have - 6,8,9,10,11 so 1 prime
  For N=5 we have - 7,9,10,11,12 so 2 prime
  For N=6 we have - 8,10,11,12,13 so 2 prime
  & so on..
  
  so 2 is common prime number,
  That why answer is 2
• 9 years agoHelpfull: Yes(1) No(0)
• ans: 4
  5, 7, 11, 13
  
• 8 years agoHelpfull: Yes(0) No(3)
• just consider n=19
  out of 20,21,22,23,24,25,26
  only 23 is prime
• 7 years agoHelpfull: Yes(0) No(0)