2,5,9,19,37,?

• Ans is 75
  here in this series c=2a+b
  2*2+5=9
  2*5+9=19
  2*9+19=37
  2*19+37=75
  
• 10 years agoHelpfull: Yes(4) No(0)
• the series goes like this: (*2)+1,(*2)-1,(*2)+1 and so on.
  (2*2)+1=5, (5*2)-1=9, (9*2)+1=18 and so on. when we reach 37, its (37*2)+1=75
• 10 years agoHelpfull: Yes(2) No(0)
• 75
  2*2=4+1=5
  5*2=10-1=9
  9*2=18+1=19
  19*2=38-1=37
  37*2=74+1=75
• 10 years agoHelpfull: Yes(1) No(0)
• 9 is odd since it is not a prime no.
• 10 years agoHelpfull: Yes(1) No(0)
• series *2+1, *2-1
  2*2+1,5*2-1,9*2+1,19*2-1,37*2+1
  ans=75
  
• 10 years agoHelpfull: Yes(0) No(0)