9 18 21 20 25

• i think (1*9)(2*9)(3*7)(4*5)(5*5)(6*3)(7*1)(8*1)is the series...
• 11 years agoHelpfull: Yes(10) No(19)
• 18-3*6 20-5*4 14-7*2
  21-3*7 25-5*5
  so next no 14
  
• 10 years agoHelpfull: Yes(2) No(1)
• 34
  18-9=9
  21-18=3
  20-21=-1
  25-20=5 now 9-3=6
  3- -1=4
  5- -1=6
  next diff will be 4
  so last term will be x-25=9 i.e. x=34
• 9 years agoHelpfull: Yes(2) No(0)
• 32 or 18
  18-9=9
  21-18=3
  12-20=1
  25-20=5
  all odd 1-9 left 7 so ans either 18 or 32
• 10 years agoHelpfull: Yes(0) No(0)
• 34 is ans
• 9 years agoHelpfull: Yes(0) No(0)
• refer this
  
  (#M40004260) IBM LOGICAL REASONING QUESTION SeriesKEEP AN EYE
  9,18,21,25,20,?
  ans is 21
  9,18 diff is 9=3^2
  21,25 diff is 4=2^2
  next diff must be 1^2=1 so 20,21
• 7 years agoHelpfull: Yes(0) No(0)