Q).Two question booklets for an aptitude test are to be given to students. In how many ways can the students be placed in two rows of six each so that there should be no identical series side by side and that, the students sitting one behind the other should have the same series ?
1) 2 × 12 C 6 × ( 6 ! ) 2
2) 6 ! × 6 !
3) 7 ! × 7 !
4) None of these

• based on given information there are 12 students,
  6 students for type-1 booklet ,
  6 students for type-2 booklet.
  there are 12 positons with each row contain 6 positions
  - - - - - -
  - - - - - -
  choose 6 students from 12 students(12c6),those 6 students can be placed in either in odd or even positions,so there are two possibilities(2C1),choosing row(2c1)and 6 students can be arranged (6!)ways
  final ans is a: 12c6*2c1*(6!)2
  
  
  
• 10 years agoHelpfull: Yes(34) No(4)
• @devendra kumar which formula
  
• 10 years agoHelpfull: Yes(2) No(0)
• 6!(2*6)=12*6!
• 10 years agoHelpfull: Yes(1) No(4)
• 12c6*2c1*6!*6!
• 10 years agoHelpfull: Yes(0) No(2)
• 12c6*2c1*6!*6!(by direct formula)
• 10 years agoHelpfull: Yes(0) No(2)