Find the odd man out
1, 3, 10, 21, 64, 129, 356, 777
A. 10 B. 21
C. 64 D. 356

• Ans:D. 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 but here it placed with 356, so it is wrong. starts with x*2+1,next x*3+1 alternately changes
• 12 years agoHelpfull: Yes(10) No(0)
• Alternate method:
  
  1=1
  3=3
  10=1+0=1
  21=2+1=3
  64=6+4=10=1+0=1
  129=1+2+9=12=1+2=3
  356=3+5+6=14=1+4=5( wrong one.. it should be 1)
  777=7+7+7=21=2+1=3
  
  Alternative 1 and 3 series..
  Ans. 356
• 11 years agoHelpfull: Yes(8) No(0)
• Ans: D. 356
  Explanation:
  series is x*2+1, x*3+1, x*2+1, x*3+1,...... where x starts with 1, and subsequently x will be previous value.
  So, 356 is wrong and must be replaced by (129 x 3 + 1) i.e. 388.
  
  
• 12 years agoHelpfull: Yes(3) No(0)
• 64 since only 64 is a perfect square
  
• 9 years agoHelpfull: Yes(0) No(0)
• Ans:D 356
  3*3+1 = 10
  10*2+1 = 21
  21*3+1 = 64
  64*2+1 = 129
  129*3+1 = 388 correct (356 - Wrong)
  388*2+1 = 777
• 8 years agoHelpfull: Yes(0) No(0)
• 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
  so wrong is 356
• 8 years agoHelpfull: Yes(0) No(0)