There are 20 persons sitting in a circle. In that there are 18 men and 2 sisters. How many arrangements are possible in which the two sisters are always separated by a man?
a. 18!x2

b. 17!
c. 17x2!

d. 12

• Now the first sister can sit in 20 ways and other sister can sit either left or right such that 2 ways .All men can sit in remaning 18 seats i.e 18!
  Answer is 18!x2
• 9 years agoHelpfull: Yes(33) No(5)
• Here 2 sisters can be assumed 1 sister,
  In this way there are total of 19 member,
  Formula for circular seating arrangement: (n-1)!
  So, (19-1)! = 18!
  But 2 sisters can also sit in 2 ways,
  Hence answer is 18! *2
• 8 years agoHelpfull: Yes(19) No(0)
• Ans is: 17!*2!
  formula for circular arrangement: (n-1)!
  so, for 18 men arrangement: (18-1)!=17!
  18 men and 2 sisters arrangement = 17!*2!
• 8 years agoHelpfull: Yes(8) No(16)
• option A is the right answer
  
• 9 years agoHelpfull: Yes(6) No(0)
• Answer is 18!*2
  The two girls can be arranged between 18 Men in 18! ways.
  Ad there positions can also be interchanged.
  So total ways are 18!*2
• 9 years agoHelpfull: Yes(6) No(2)
• first learn this question thoroughly here they asked for no of arrangements not for probability so first given data is:
  18m and 2sis ,take 2 sisters as one unit such that they are total of 19units which as byformula
  (n-1)!therefore (19-1)!*2! =18!*2 (2! is such that 2 sisters can be arranged among them selves seperated from man in 2!ways)
• 8 years agoHelpfull: Yes(3) No(0)
• since two sisters are always separated by one man so fix these three ( two sisters and a man in middle), now 17 man are left which can be arranged in 17! ways and two sisters can be arranged around the man in 2 ways.
  so, total no of arrangements = 17! * 2
• 8 years agoHelpfull: Yes(3) No(1)
• 17!*2
  consider the circle=(n-1)!
• 8 years agoHelpfull: Yes(2) No(2)
• Let the first sister name is A. Now she can sit any where in the 20 places (Symmetrical). Now her sister B can sit to her left or right in 2 ways. Now the remaining 18 persons can be sit in 18 places in 18! ways. Total = 18! × 2
• 8 years agoHelpfull: Yes(1) No(1)
• answer should be A.because here not talking about men.
  so men are sitting in !18 AND two sister in 2! ways
• 8 years agoHelpfull: Yes(1) No(0)
• the first sister name is A. Now she can sit any where in the 20 places (Symmetrical). Now her sister B can sit to her left or right in 2 ways. Now the remaining 18 persons can be sit in 18 places in 18! ways. Total = 18! × 2
• 8 years agoHelpfull: Yes(1) No(0)
• First 18 men can sit to the table in (18-1)! ways that means 17! ways and the remaning places 2 can be arrange by two girls in 2p2 ways=2! ways.so the answer is 17!*2! i.e, 17!*2 ways.so the option c is the right answer
• 8 years agoHelpfull: Yes(1) No(0)
• 18!*2
  s-m-s one set
  rem 17+one set=18
  circle=17!
  men=18
  17!*18*2=18!*2
• 7 years agoHelpfull: Yes(1) No(1)
• a.probablity
  
• 9 years agoHelpfull: Yes(0) No(1)
• 18!*2
  Because 18 Not multiple of 2
  2 is sisters are women it is not include in men.
• 8 years agoHelpfull: Yes(0) No(0)
• Ans a because of 18 members sitting
• 8 years agoHelpfull: Yes(0) No(0)
• two sisters asssumed one unit so total no. of ways=19
  so no. of arrangements=18!
  so answer is 18!*2
• 8 years agoHelpfull: Yes(0) No(0)
• nithiya 758b 3456
• 8 years agoHelpfull: Yes(0) No(0)
• assume that one seat consider as sister1 men sister2 and remaining seat are 17 seats so, total seat are 18
  seating arrangement are 18! and both sisters can exchange their position in 2 ways then
  the answer is 18!*2
• 7 years agoHelpfull: Yes(0) No(0)