Find the missing number:
6 9 12 ? 6

• 6 9 12 9 6
  palindrome !!!!!!!!
• 12 years agoHelpfull: Yes(54) No(2)
• ans 6+3 9+3 12+3=15 simple
• 13 years agoHelpfull: Yes(7) No(83)
• 6 9 12 9 6
• 12 years agoHelpfull: Yes(7) No(3)
• The numbers can be arranged like +3,+3,-3,-3 format. So the number next to 12 in the series 6 9 12 _ 6 is 6 only.
• 12 years agoHelpfull: Yes(5) No(15)
• 6 9 12 9 6
• 12 years agoHelpfull: Yes(3) No(1)
• 6 9 12 9 6
  
  ans: 9
• 12 years agoHelpfull: Yes(2) No(1)
• 9
  series is +3 and -3
• 12 years agoHelpfull: Yes(1) No(2)
• 6+3=9
  9+3=12
  12-3=9
  9-3=6
  
  therefore ans=9
• 12 years agoHelpfull: Yes(0) No(0)
• 9 because first 3 numbers adding by 3 and then subtract by 3
  
• 12 years agoHelpfull: Yes(0) No(0)