9 boys and girls,9 seats 1st sits ,2nd sits just next to 1st on any of the two sides,3rd sits just next to either of two.........and so on.In how many ways can they sit

• i think it can be solved this way.. not sure though..
  if the first one to sit sits at one end then.. everybody will hav only 1 way to sit... ie 1*1*1*1*1*1*1*1 =1
  now if he sits in 2 nd seat then second person will have 2 ways and the rest will have 1 way.. which =2
  now if he sits in the 2nd seat 2nd and 3rd person will be having 2 chances each so it will be 4 if this is continued..
  1+2+4+6+8+6+4+2+1=21+21=42 ways.. pls correct me if i am wrong
  
• 11 years agoHelpfull: Yes(1) No(1)