Find out the wrong term in the series given below:-
11, 5, 20, 12, 40, 26, 74, 54

• consider alternate numbers.
  5 12 26 54, differences are doubling 7 14 28.
  for 11 20 40 74 differences are 9 20 34
  if number 40 is made 38
  11 20 38 74, differences are 9 18 36
  so wrong term is 40.
• 13 years agoHelpfull: Yes(4) No(2)
• 38 is wrong term.
  
  11, 5, 20, 12, 40, 26, 74, 54
  
  two series are
  11,20,40,74 ...
  and
  5,12,26,54
  
  In case of 11,20,40,74 ...
  20 = 11*2-2
  next number should be 20*2-2=38
  as 74= 38*2-2
  
  so wrong term is 40 which should be 38.
• 13 years agoHelpfull: Yes(3) No(1)
• Take the pair of terms
  11+5=16
  20+12=32
  40+26=66
  74+24=128
  Except the pair(40,26) all other are divisible by 16
  12-5=7
  26-12=14
  54-26=28
  from the above we know that 26 is placed correct
  so the answer is 40
• 13 years agoHelpfull: Yes(1) No(1)
• Take the alternate terms:
  11, 20, 40, 74
  and 5, 12, 26, 54
  
  The difference between the first sequence of nos. are
  
  11 (9) 20 (20) 40 (34) 74 ---------- A
  
  and 5 (7) 12 (14) 26 (28) 54 ----------- B
  
  From ' B ' we can see that the difference between the nos.(i.e. within brackets) are increasing by double...
  
  Similarly, for ' A ' also to exhibit the similar property, 40 should be corrected to "38"...
  
  Hence sequence ' A ' will become,
  
  11 (9) 20 (18) 38 (36) 74
  
  Now we can see that the difference between the nos. make sense!!!!
  
  40 is the faulty no. Make it 38...
• 13 years agoHelpfull: Yes(0) No(0)