Q. Find incorrect number
7, 8, 18, 57, 228, 1165, 6996

• Look upon the series carefully
  7,
  [7+1]*1 = 8
  [8+1]*2 = 18,
  [18+1]*3 = 57
  [57+1]*4 = 232.......
  
  so 228 is incorrect.
  
  [232+1]*5 = 1165
  [1165+1]*6 =6996
• 11 years agoHelpfull: Yes(5) No(0)
• 228 is incorrect.
  7,
  (7+1)*1=8
  (8+1)*2=18,
  (18+1)*3=57
  (57+1)*4=232....... so 228 is incorrect.
  (232+1)*5=1165
  (1165+1)*6=6996
• 11 years agoHelpfull: Yes(2) No(1)
• 7,7*1+1=8,8*2+2=18,18*3+3=57....thus 228 is wrong answer
• 11 years agoHelpfull: Yes(1) No(1)
• 228 is wrong.
  1-->7
  2-->7*1+1=8
  3-->8*2+2=18
  4-->18*3+3=57
  5-->57*4+4=232 but here 228
  6-->232*5+5=1165..
  so on....
• 11 years agoHelpfull: Yes(0) No(0)
• (1*7)= 7
  (1*7)+1 =8
  (2*8)+2 =18
  (3*18)+3= 57
  (57*4)+4 =232...
  So the number 228 is incorrect..
  
  (232*5)+5 =1165...
• 10 years agoHelpfull: Yes(0) No(0)