12,3,15,14,6,19,9,18,12,21

• Ans=27
  12+3=15-0=15
  14+6=20-1=19
  16+9=25-2=23
  18+12=30-3=27
• 7 years agoHelpfull: Yes(8) No(18)
• sIt should be 12,3,15,14,6,19,16,,9,23,18,12 you missed the 16 after 19.
  if so It’s just three simple series,
  12 14 16 18
  3 6 9 12
  15 19 23 x
  15+4=19 19+4=23 23+4=27
  so ans is x=27.
• 7 years agoHelpfull: Yes(7) No(4)