In how many ways 3 boys can be placed in 9 seats in a single row,such that no two boys are adjacent to each other.

• they can be either arrange at odd places or at even places
  1:if they are arranger at odd (1,3,5,7,9)5p3
  2:if they are arranged at even places(2,4,6,8)4p3
  so 5p3+4p3=54
• 11 years agoHelpfull: Yes(48) No(25)
• the boys can be made to sit at odd places or evenplaces;to do this:
  5c3*3!+4c3*3!
• 11 years agoHelpfull: Yes(12) No(12)
• 5c3*3! + 4c3*3! as at odd places they can take any 3 seats out of 5 similarly for even places
• 11 years agoHelpfull: Yes(7) No(2)
• If we arrange them in even and odd places, we may miss the cases in which two boys are seperated by two or more places.
  Hence the ans can be obtained as Total arrangements-No.of arrangements they sit together
  i.e., 9p3-9c1*3!=450
  
• 11 years agoHelpfull: Yes(6) No(1)
• ans 35????
• 11 years agoHelpfull: Yes(5) No(1)
• no. of ways in which 3 boys can sit in 9 seats=9C3
  no. of ways in which 3 boys will sit together=7C1*3!
  no. of ways in which 2 boys will sit together=8C2*2!, out of which there is '1' arrangement in which the 3 boys will be sitting together.
  No. of ways=9C3-(7C1*3!+8C2*2!-1)
• 11 years agoHelpfull: Yes(2) No(0)
• majak chal raha hai kya!
• 11 years agoHelpfull: Yes(2) No(0)
• 5p3*3!+4p3*3!...........this is the answer
• 10 years agoHelpfull: Yes(2) No(0)
• 9c3*3! - (7c1*3! + 8c2*2! - 1) = 407
• 9 years agoHelpfull: Yes(2) No(1)
• its 9c3-8p2*3c2*2!=504-56*6=168
• 11 years agoHelpfull: Yes(1) No(2)
• first person can sit in 9 ways where c0ming to second person if first person occupies extreme position so he has 7 positions and similarly in the case of 3rd person so
  9*7*4+9*6*5+9*6*4=738
• 11 years agoHelpfull: Yes(1) No(1)
• admin please give correct solution for this ques
• 9 years agoHelpfull: Yes(1) No(0)
• 9
  c - 3 =81
  3
• 11 years agoHelpfull: Yes(0) No(4)
• is 34 z d ans?
• 11 years agoHelpfull: Yes(0) No(2)
• 5c1 + 4c3 Ans.
• 11 years agoHelpfull: Yes(0) No(1)
• 7c3 is d answer
  
• 11 years agoHelpfull: Yes(0) No(0)
• 9c3*3! - (7c1*3! + 8c2*2! - 1) = 407
• 9 years agoHelpfull: Yes(0) No(0)
• 9c3*3! - (7c1*3! + 8c2*2! - 1) = 407
• 9 years agoHelpfull: Yes(0) No(0)
• 9c3*3! - (7c1*3! + 8c2*2! - 1) = 407
• 9 years agoHelpfull: Yes(0) No(0)
• 9c3*3! - (7c1*3! + 8c2*2! - 1) = 407
• 9 years agoHelpfull: Yes(0) No(0)
• 9c3*3! - (7c1*3! + 8c2*2! - 1) = 407
• 9 years agoHelpfull: Yes(0) No(0)
• B S B S B S B S B S B S B
  7C4=35
  
• 9 years agoHelpfull: Yes(0) No(1)
• CORRECT ANS IS 84
• 3 years agoHelpfull: Yes(0) No(0)