Find out the wrong number in the series.
1, 3, 10, 21, 64, 129, 356, 777

A. 10 B. 21
C. 64 D. 129
E. 356

• option E 356
  1*2+1=3
  3*3+1=10
  10*2+1=21
  21*3+1=64
  64*2+1=129
  129*3+1=388
  388*2+1=777
• 12 years agoHelpfull: Yes(6) No(1)
• 1*2+1=3
  3*3+1=10
  10*2+1=21
  21*3+1=64
  64*2+1=129
  129*3+1=388
  thus option E 356.
• 11 years agoHelpfull: Yes(1) No(0)
• 356.........................................................................
• 10 years agoHelpfull: Yes(1) No(0)
• E 356
  Because 1*2+1=3
  3*3+1=10
  10*2+1=21
  21*3+1=64
  64*2+1=129
  129*3+1=388
  388*2+1=777
• 7 years agoHelpfull: Yes(0) No(0)