26,19,17,13,11,?,8,7

• Here consider 26,17,11,8 as a one sequence,
  in this sequence difference between consecutive no. is 9,6,3
  now consider 19,13,?(X),7 as a second sequence,let ? is X
  difference between 19 & 13 is 6, diff. btwn 7 & 13 is 6 , then X must be 9.
  so the series will be 19,13,9,7 & difference is 6,4,2
  Then the missing number is 9.
  
• 10 years agoHelpfull: Yes(23) No(2)
• Ans:9
  By considering 7 ? 13 19; one sequence and 8 11 17 26 another sequence
  difference------6 --------3--6--9----------
  So for the first sequence difference between 7 and 13 is 6; if we consider it to be 2+4;
  then the missing no. is 9
• 10 years agoHelpfull: Yes(5) No(5)
• 7 8 9 11 13 17 19 26
  Addition of differnce continiously
• 6 years agoHelpfull: Yes(0) No(0)