8 6 17 14 35 30 71 ? 143.

• Soln. = 62
  Expl. = It sequenced in two series.
  1st series(8 17 35 71)[it increased as +9 +18 +36 +72....like that]
  2nd series(6 14 30 62)[it increased as +8 +16 +32 ........like that]
  
  $ Vignesh(India, TamilNadu) $
• 13 years agoHelpfull: Yes(10) No(0)
• 8-6=2
  17-14=3
  35-30=5
  71-x=7(results in the prime series) so
  x=64
• 12 years agoHelpfull: Yes(1) No(4)
• here ans is 78
• 13 years agoHelpfull: Yes(0) No(5)