1,3,4,5,10,9,19,15,?

• take 2 different series
  1)1,4,10,19,?
  and 2) 3,5,9,15
  so in 1st series 1,1+3,1+3+6,1+3+6+9,1+3+6+9+12=31
  ans=31
• 8 years agoHelpfull: Yes(15) No(0)
• 1 st digit+3= 3rd digit
  3rd digit+6=5th digit
  5th digit+9=7th digit
  7th digit+12=9th digit(31 ans)
  
  
• 8 years agoHelpfull: Yes(13) No(2)
• 31
  1,3,4,5,10,9,19,15,31
  1-3=1+3=4
  4-10=4+6=10
  10-19=10+9=19
  19-31=19+12=31
  
• 8 years agoHelpfull: Yes(6) No(1)
• starting from 1 alternate numbers are multiples of 3 in series and adding that number with 1
• 8 years agoHelpfull: Yes(2) No(0)
• 31
  take 1,4,10,19 one set t difference is 3,6,9,so next 12
  add 19+12 we get 31 ans
• 8 years agoHelpfull: Yes(1) No(0)
• 1,3,4,5,10,9,19,15 ...odd position difference is multiple of 3 so answer is 31
• 8 years agoHelpfull: Yes(0) No(0)
• 31
  1+3=4
  4+(3*2)=10
  10+(3*3)=19
  19+(3*4)=31
  
  3+2=5
  5+(2*2)=9
  9+(2*3)=15
  Observe Alternative series
• 6 years agoHelpfull: Yes(0) No(0)
• 1 st digit+3= 3rd digit
  3rd digit+6=5th digit
  5th digit+9=7th digit
  7th digit+12=9th digit(31 ans)
• 6 years agoHelpfull: Yes(0) No(0)
• Take two series
  1)1,4,10,19,? { [1-4=3,4-10=6,10-19=9] So,differeneces are 3,6,9 the next number will be 12. So, add 12+19=31 }
  
  2)3,5,9,15
• 6 years agoHelpfull: Yes(0) No(0)
• 31,1+4+10+19+31,odd place gap increase by 3 multiple
• 4 years agoHelpfull: Yes(0) No(0)