Q. What is the next no of following series
9, 12, 4, 8, 12, 15, 5, 9, 3, 6, 2, 6, 6, 9, ?

• Look Upon the series carefully
  9, 12..... 4, 8..... 12, 15...... 5, 9..... 3, 6..... 2, 6,...... 6, 9,
  (3)...... (4)..... (3) ...... (4) ..... (3) ..... (4) ...... (3)
  
  9 + 3 = 12, 12/3=4, 4+4=8
  12+ 3 = 15, 15/3=5, 5+4=9
  3+3=6, 6/3=2, 2+4=6
  similarly,
  6+3=9, 9/3=3, 3+4=7
  
  so next no will be 3,7
  
  
  
• 10 years agoHelpfull: Yes(32) No(2)
• Make pairs as follows:
  (9,12,4,8),(12,15,5,9),(3,6,2,6),(6,9,_,_)
  9+3=12, 12/3=4, 4+4=8
  12+3=15, 15/3=5, 5+4=9
  3+3=6, 6/3=2, 2+4=6
  similarly,
  6+3=9, 9/3=3, 3+4=7
  the next pair is 6,9,3,7
  Answer. 3
  
  
• 10 years agoHelpfull: Yes(11) No(0)
• (9,12)(4,8)(12,15)(5,9)(3,6)(2,6)(6,9) each pair has difference of 3,4 respectively,and observe the alternate patterns..
  (9,12)(12,15)(3,6)(6,9)
  (9,12),(9+3,12+3)---> (12-9,15-9)--->(3+3,6+3)--->(6-9,+9-9)=(-3,0)
  (4,8)-->(4+1,8+1)-->(5-3,9-3)-->(2+1,6+1)
  therefore the next four terms would be 3,7,-3,0
• 10 years agoHelpfull: Yes(5) No(2)
• 9, 12, 4, 8, 12, 15, 5, 9, 3, 6, 2, 6, 6, 9
  here a pattern is visible
  9 12 (+3)
  4 8 (+4)
  12 15 (+3)
  .
  .
  .
  6 9 (+3)
  ?
  now as we can se the terms on the left hand side are
  9= 3*3 next term after 9 is (3+1)
  12= 3*4 next term after 12 is (4+1)
  3= 3*1 next term after 3 is (1+1)
  6= 3*2 next term after 6 WILL BE (2+1) = 3
  SO THE SERIES WOULD BE
  9, 12, 4, 8, 12, 15, 5, 9, 3, 6, 2, 6, 6, 9, 3, 7
  
• 10 years agoHelpfull: Yes(0) No(3)
• (12-9)=3,4
  12-8=4,15
  9-5=4,3
  2-6=-4,6
  9-6=3,4
  next no is 4
• 10 years agoHelpfull: Yes(0) No(1)
• 48/24=2; 35/7=5
  16/8=2; 75/15=5
  80/40=2; x/y=5
  
  if we observe 35,75,x are in series with a difference of 40. so x=75+40=115
  similarly 7,15,y are in series with a difference of 8. so y=15+8=23
  
  x/y=115/23=5 It satisfies the problem so next two terms are 115 & 23.
  
• 9 years agoHelpfull: Yes(0) No(1)