Q. What is the next number of the following sequence
6,9,18,45,108,351,....

• ans 1080
  difference b/w each number is 3 9 27 81...respectively
  so 351-108=243
  so 243*3=729 that is added to 351 so ans is 1080
• 10 years agoHelpfull: Yes(6) No(22)
• ans 792
  difference b/w each number is 3 9 27 63 243...respectively
  now in the odd positions 3 27 243 and in the even positions 9 63...
  (3*9=27, 27*9=243 ) ( 9*7=63 , 63*7=441)
  
  Now the even position series 9,63,441 and difference between nos are 3 9 27 63 243 and 441
  so 351+441=792(ans)
• 8 years agoHelpfull: Yes(4) No(0)
• 3*(6-3)=9
  3*(9-3)
  .
  .
  .
  3*(351-3)=1044.
• 10 years agoHelpfull: Yes(1) No(12)