In this question, one term in the number series is wrong. Find out the wrong term
1, 5, 5, 9, 7, 11, 11, 15, 12, 17



A. 11
B. 12
C. 17
D. 15

• There are two series together mixed alternatively,
  1,5,7,11,12
  5,9,11,15,17
  Both series have the rule of adding +4 then +2 alternatively,
  Like 5, 5+4=9, 9+2=11, 11+4=15, 15+2=17
  But in the first series, 1, 1+4=5, 5+2=7, 7+4=11, 11+2=13 not 12 , so the wrong term is 12.
• 7 years agoHelpfull: Yes(21) No(1)
• all the numbers are odd except 12
  
• 7 years agoHelpfull: Yes(8) No(0)
• b
  all are prime numer except 12
• 7 years agoHelpfull: Yes(5) No(27)
• 1+4=5
  5+4=9
  7+4=11
  ......
  ......
  but 12+4=16 but next no is 17
  so ans is C i.e 17
• 7 years agoHelpfull: Yes(3) No(5)
• 1,5,7,11,12
  1+4=5
  5+2=7
  7+4=11
  11+2=13
  5,9,11,15,17
  5+4=9
  9+2=11
  11+4=15
  15+2=17
  
• 7 years agoHelpfull: Yes(3) No(2)
• can anyone solved this question?
  
• 7 years agoHelpfull: Yes(1) No(1)
• ans B) Since substraction of all consecutive terms is in power of two but not 12-15=3 & 17-12=5 .
• 7 years agoHelpfull: Yes(1) No(0)
• 1+4=5
  5+4=9
  9+4=11
  11+4=15
  13+4=17
  odd number + 4 = odd number
  option = B
• 7 years agoHelpfull: Yes(1) No(0)
• Ans is B..just because there are 2 series 1,5,7,11,12 and 5,9,11,15,17. In first series there is 1+4=5 then 5+2=7 then 7+4=11 then there should be 11+2=13,but there is 12.So it is wrong.
• 7 years agoHelpfull: Yes(1) No(0)
• 1 ,5 ,5 ,9 7 11 11 15 12
  +4 0 +4 -2 +4 0 +4 (-3 ) but according to deduction it should have been (-2)
  so 12 is wrong number in series
  13 should be there in place of 12
• 7 years agoHelpfull: Yes(1) No(0)
• Ans- 12 because all no are odd numbers except 12 is a even no.
• 7 years agoHelpfull: Yes(1) No(1)
• B.12 is the correct ans guys bcoz 12 has lots of factor & also go wid the given option.
  
• 7 years agoHelpfull: Yes(0) No(0)
• (1,5,5,9),(7,11,11,15),(12,17,....)
  here series is like 5+5-9=1
  11+11-15=7
  difference b2n two same number is 6. so in the third series 17 is correct 11+6=17
  bt first term should like 1,7,13 with difference 6
  so the wrong term is 12.
  and the actual series will look like (1,5,5,9),(7,11,11,15),(13,17,17,21)
• 5 years agoHelpfull: Yes(0) No(0)