n is the natural number greater than 99 such that it has only 2 factors k and k-2( other than 1 and N itself ) .the last digit of any such number n is called "ntail". "ntail" can take how many differnt values?

• 2 diff values
  n can be either 3 or 9 only.
  
  k & (k-2) should be 2 consecutive primes
  ex- 11*13 ------3
  29*31 -----9 etc
• 8 years agoHelpfull: Yes(12) No(3)
• ans will be 2
  
  last digit can be 9 (29 and 31)
  or last digit can be 3(17 and 19, 11 and 13)
• 8 years agoHelpfull: Yes(1) No(0)
• options are -a-1 b-2 c-3 d-4
• 8 years agoHelpfull: Yes(0) No(0)
• k*k-2=n>99 ..by solving this eqn. we have . k>11 or K
• 8 years agoHelpfull: Yes(0) No(0)
• ans is a
  becoz-- as we can calculate k>11 for which we have only two facotors 11,13 and other 17 ,19 that give 3 at its unit place
• 8 years agoHelpfull: Yes(0) No(3)
• only 2 values 1 and 3
• 8 years agoHelpfull: Yes(0) No(0)