3, 22, 7, 45, 15,? , 31
a)91 b)151 c)90 d)5

• 3*2+1=7
  22*2+1=45
  7*2+1=15
  then
  45*2+1=91 answer
• 8 years agoHelpfull: Yes(11) No(0)
• 3*2+1=7,22*2+1=45,7*2+1=15,45*2+1=91
• 8 years agoHelpfull: Yes(5) No(0)
• 38*2+15=91
• 8 years agoHelpfull: Yes(1) No(0)
• ans 91
  take the odd positions:
  22+22+1=45
  45+45+1=91
  so ans 91
• 8 years agoHelpfull: Yes(1) No(0)
• In this series 1,3,5,7 and so on ...is make a series and 2,4,6,8...so on make a series.
  3*2+1=7
  7*2+1=15
  15*2+1=31
  22*2+1=45
  45*2+1=91
  So the answer is 91
• 8 years agoHelpfull: Yes(0) No(1)
• the answer is 91.
  bcz 22+23=45;
  45+45=91;
  3+4=7;
  7+8=15;
• 8 years agoHelpfull: Yes(0) No(1)
• this series has two seperate series.
  3*2+1=7
  7*2+1=15
  same as
  22*2+1=45
  45*2+1=91
  so answer is 91
  
• 8 years agoHelpfull: Yes(0) No(1)