9,3,6,21,9,12,33,15,18,?

• 45,21,24...add first number by 12, 2nd,3rd by 6..........
  
  it is a series with 3 subseries
  
• 11 years agoHelpfull: Yes(36) No(3)
• (3*1)+(3*2)=9
  (3*3)+(3*4)=21
  (3*5)+(3*6)=33
  (3*7)+(3*8)=45
• 11 years agoHelpfull: Yes(21) No(3)
• here there are two series one is
  3,6,9,12,15,18 which is multiple of 3
  and secpnd one is 9,21,33,? which is created by adding 12 in each term like
  9+12=21
  21+12=33
  33+12=45
  so 45 is ans.
• 11 years agoHelpfull: Yes(15) No(0)
• 9,21,33,45
  3,9,15
  6,12,18
  ans=45
• 11 years agoHelpfull: Yes(9) No(0)
• in my first solution mistake
  9,21,33,45 (all diff is 12) ans =45
• 11 years agoHelpfull: Yes(4) No(0)
• 9,3,6,21,9,12,33,15,18,?
  3+6=9,
  9+12=21,
  15+18=33,
  22+23=45.
  
• 11 years agoHelpfull: Yes(3) No(3)
• 9,3,6(3rd no=1st-2nd)
  21,9,12(3rd no=1st-2nd)
  33,15,18(3rd no=1st-2nd)
  for find the next number: 9,21,33,43(diff like 12,11,then 10) ans =43
  
  
• 11 years agoHelpfull: Yes(1) No(5)
• 9-3=6 , 21-9=12,33-15=18.
  Now
  Diff between 9 and 21 =12
  Diff between 21 and 33 =12
  So 33+12=45
• 7 years agoHelpfull: Yes(1) No(0)
• (9,3,6)-->(9-3=6)-->9+(4*3)=21-->3+(3*2)=9
  (21,9,12)-->(21-9=12)-->21+(4*3)=33-->9+(3*2)=15
  (33,15,18)-->(33-15=18)-->33+(4*3)=45-->15+(3*2)=21
  (45,21,24)-->(45-21=24)
  
• 11 years agoHelpfull: Yes(0) No(0)
• divide the series in 3 groups (9,3,6), (21,9,12), (33,15,18)....
  9=3+6
  21=9+12
  33=15+18
  now there is a relation among 9,21,33 :
  3*3=9
  3*7(i.e 3+4)=21
  3*11(i.e 7+4)=33
  3*15(i.e 11+4)=45
  hence 45 is the ans.
• 10 years agoHelpfull: Yes(0) No(0)
• 9,3,6,21,9,12,33,15,18,____ ?
  (9,3,6) (21,9,12) (33,15,18)
  
  21-9=12
  33-21=12
  x-33=12 =>x=33+12 =>45
• 6 years agoHelpfull: Yes(0) No(0)