Complete the sequence 9,10,11,13,15, __, 21,28.

• 19
  
  9,10,11,13,15, __, 21,28.
  9,10,11,13,15, 19, 21,28.
  
  there are 2 series.
  9,11,15,21 ... with difference in numbers 2,4,6,8 and 10,13,19,28.. with diff in numbers 3,6,9
• 12 years agoHelpfull: Yes(23) No(0)
• 19
  first series 9(+2)11(+4)15(+6)21
  second series 10(+3)13(+6)"19"(+9)28 :)
• 12 years agoHelpfull: Yes(3) No(1)
• 9+2=11
  10+3=13
  11+4=15
  therefore 13+5=18 is the answer
• 12 years agoHelpfull: Yes(2) No(2)
• ans is 18
  9+1=10
  10+1=11
  11+2=13
  13+2=15
  15+3=18
  18+3=21
  
  
• 12 years agoHelpfull: Yes(1) No(6)
• 35,42
  series is fibonacci.....
  
• 12 years agoHelpfull: Yes(0) No(5)
• 18
  seq.1 1 2 2 3 3
• 12 years agoHelpfull: Yes(0) No(4)
• 
  9,10,11,13,15, __, 21,28
  
  d difference of 9 nd 10 is 1 ..
  " " " 10 nd 11 is 1 ..
  " " " 11 nd 13 is 2 ..
  " " " 13 nd 15 is 2 ..
  " " " 15 nd _ is ..?
  
  so here v add 3 d ans is 18 .....
  
  " " " 18 nd 21 is 3 .. BY - MK -
• 12 years agoHelpfull: Yes(0) No(3)
• ans is 18 bcz there is differnce between no.s is 1 1 2 2 3 3.......n so on
  
• 9 years agoHelpfull: Yes(0) No(0)