Q. COMPLETE THE SERIES..
1, 3, 7, 11, 13,... ?

• i think in this series we need to divide series in two parts i.e in terms of even place term and odd place term.i.e
  1,7,13 so in odd term you see a difference of 6.
  and in even terms there is difference of 8
  3,11 so next term will be 11+8=19.
  so series is like this
  1,3,7,11,13,19.
• 10 years agoHelpfull: Yes(31) No(8)
• 1^2-0=1
  2^2-1=3
  3^2-2=7
  4^2-3=13
  5^2-4=21
• 10 years agoHelpfull: Yes(31) No(25)
• difference between numbers i think
  3-1=2
  7-3=4
  11-7=4
  13-11=2
  so,
  next numbers is 17
  because 17-13=4
  21-17=4
  23-21=2
  so ans is 17.
  its right or not.plz reply
• 10 years agoHelpfull: Yes(19) No(14)
• answer is 17
  1,3,7,11,13...
  
  1 3 7 11 13 17
  
  +2 +4 +4 +2 +4
• 10 years agoHelpfull: Yes(9) No(4)
• Ans is 17 since all are prime numbers written in ascending order
• 10 years agoHelpfull: Yes(8) No(5)
• this is a series of prime numbers.
  The next prime number after 13 is 17 .
  hence 17 is the answer.
• 10 years agoHelpfull: Yes(4) No(7)
• ans is 17
  here series is getting added with 2,4,4,2,4,4 and its repeating like that.
  1+2=3
  3+4=7
  7+4=11
  11+2=13 series is repeating here again
  so next term is 13+4=17
• 10 years agoHelpfull: Yes(2) No(1)
• 17
  13+4=17
  the diff. in series is 2,4,5 and thn 2
• 10 years agoHelpfull: Yes(1) No(3)
• which is the correct answer 21 or 17
• 10 years agoHelpfull: Yes(1) No(1)
• neha there 11 is missing..ans is 17
• 9 years agoHelpfull: Yes(1) No(0)
• ans is 19 the series has two series 1,7,13 diff=6
  3,11.. diff =8
  so ans is 11+8=19
  
• 10 years agoHelpfull: Yes(0) No(3)
• it is the series of odd prime numbers, so next number must be 17
• 10 years agoHelpfull: Yes(0) No(0)
• 1 3 7
  11 13 17
  
• 10 years agoHelpfull: Yes(0) No(0)
• all prime no. is in assecending order so ans is 17 .
  
  2nd explanation
  diff is in order 2 ,4 ,4,2 so next no. will be 13+4=17
• 7 years agoHelpfull: Yes(0) No(0)
• 2 & 4 add so next is 17
• 7 years agoHelpfull: Yes(0) No(0)
• 1 3 7 11 13 17
  +2 +4 +4 +2 +4
• 4 years agoHelpfull: Yes(0) No(0)