2, 3, 5, 7, 11, ?, 17
1] 12 2] 13
3] 14 4] 15

• 2] 13
  it is the series of prime numbers
  2, 3, 5, 7, 11, 13, 17
  
  
• 10 years agoHelpfull: Yes(18) No(0)
• Answer 15
  2-5=3,5-11=6
  3-7=4,7+8=15
• 10 years agoHelpfull: Yes(2) No(5)
• 13, all are prime numbers
  
• 10 years agoHelpfull: Yes(2) No(0)
• series of prime n.os
  2,3,5,7,11,13,17,19
  so answer is 13
  
• 10 years agoHelpfull: Yes(1) No(0)
• 1+1=2
  2+1=3
  3+2=5
  5+2=7
  7+4=11
  11+4=15.
• 10 years agoHelpfull: Yes(1) No(5)
• 13,
  all are prime numbers starting as 2,3,5,7,11,13,17
• 10 years agoHelpfull: Yes(1) No(0)
• 13.all are prime numbers
• 10 years agoHelpfull: Yes(0) No(0)
• 13...all are prime numbers
  
• 10 years agoHelpfull: Yes(0) No(0)
• 13... the prime numbers...
• 10 years agoHelpfull: Yes(0) No(0)
• 13.all are prime numbers
• 10 years agoHelpfull: Yes(0) No(0)
• answer is b)13
  because it's a series of prime nos.
• 10 years agoHelpfull: Yes(0) No(0)
• 2] 13
  as it is a series of prime numbers
• 10 years agoHelpfull: Yes(0) No(0)
• 2 prime number
• 10 years agoHelpfull: Yes(0) No(0)
• 13........
  13 is prime no.....above list uses only prime no's as a series
• 10 years agoHelpfull: Yes(0) No(0)
• Ans is : 13
• 10 years agoHelpfull: Yes(0) No(0)
• 13 is placed b/w 11&17
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  7
• 10 years agoHelpfull: Yes(0) No(6)
• 
  2+1=3
  3+2=5
  5+2=7
  7+4=11
  11+4=15
  15+2=17
  
  Ans is 15
• 10 years agoHelpfull: Yes(0) No(9)
• 13.it is a prime number series
• 10 years agoHelpfull: Yes(0) No(0)
• answer is 15
• 10 years agoHelpfull: Yes(0) No(0)
• 13 series of prime numbers 2,3,5,7,11,13,17
• 10 years agoHelpfull: Yes(0) No(0)
• 2] 13
  because series is all about continuous prime numbers..
• 10 years agoHelpfull: Yes(0) No(0)
• it is the series of prime number.....ans is 13.
• 10 years agoHelpfull: Yes(0) No(0)
• 2 z d option,bcz all are consicutive prime numbers
• 10 years agoHelpfull: Yes(0) No(0)
• 13 answer
  
• 10 years agoHelpfull: Yes(0) No(0)
• ANs is2)13
• 9 years agoHelpfull: Yes(0) No(0)
• prime number series 13
• 9 years agoHelpfull: Yes(0) No(0)
• 13 becoz the series is prime number pattern
  
• 9 years agoHelpfull: Yes(0) No(0)
• 13..series of prime numbers
• 9 years agoHelpfull: Yes(0) No(0)