17,18,19,34,35,19,20,___

• (17,18) 19 (34,35) 19 (20,?)
  18-17=1
  35-34=1
  x-20=1 =>x=21
  
  ans is 21
• 11 years agoHelpfull: Yes(14) No(0)
• 17,18,19 are in series,after dat 2 numbers are in series next the 3 series will be repeated so ans:21
• 13 years agoHelpfull: Yes(5) No(2)
• 19 is common alternative...
  17+1=18
  34+1=35
  so
  20+1=21
• 8 years agoHelpfull: Yes(1) No(0)