which term in following does not belong to the sequence formed by rest
7,9,17,42,91,172,293.

options
a)17
b)9
c)91
d)42

• i am not sure but it should be b) 9
  because from 17 on-wards the difference between two terms is the square of an odd number starting from 5 such 42 -17 = 25 --> 5^2
  91-42 = 49 --> 7^2
  172-91 = 81 --> 9^2
  but starting two terms 7 and 9 doesn't make sense so they are different from the sequence. 9 is available in the option also. so b) 9 is the solution.
• 10 years agoHelpfull: Yes(28) No(1)
• 7+1^2=8
  8+3^2=17
  17+5^2=42
  42+7^2=91
  91+9^2=172
  172+11^2=293
  
  So the answer will be 9
• 9 years agoHelpfull: Yes(7) No(0)
• wrong 9.
  42 -17 = 25 --> 5^2
  91-42 = 49 --> 7^2
  172-91 = 81 --> 9^2
• 10 years agoHelpfull: Yes(5) No(1)
• I think the wrong is 9, since 7 is not given in option so i am 100% sure !!!
• 10 years agoHelpfull: Yes(2) No(2)
• in ths series only 9 hv a perfect square so 9 should be the ans
  and bro i m 10000% sure;;;;;:)
• 10 years agoHelpfull: Yes(1) No(0)
• 1^2 3^2 5^2 7^2 9^2 11^2 .. in place of 9 there would be 8
• 9 years agoHelpfull: Yes(0) No(0)
• 7+1^2=8
  8+3^2=17
  17+5^2=42
  42+7^2=91
  91+9^2=172
  172+11^2=293
  
  So the answer will be 9
• 9 years agoHelpfull: Yes(0) No(0)
• answer is option b -9 as it is clearly seen it forms an progression
• 9 years agoHelpfull: Yes(0) No(0)