7 indians,4americans,2germans are to be seated on 13 chairs for a photograph if a photograph is clicked .what is the probability that in the photo no 2 indians are together
a)7!4!2!/13!
b)7!6!/13!
c)7!/13!
d)7/123

• HERE consider germans and americans as 1 unit.ie..together.so there are 6 american-german and 7 indians.
  now...first arrange 6 american german on alternate chair.
  so,there is 6! way of arranging them.
  now there are 7 place in between american-german...
  now in that 7 place indians can be seated in 7! ways.
  so favourable outcome=7!*6!
  total outcome=13!
  hence probablity=(7!*6!)/13!
  option b) is correct
• 9 years agoHelpfull: Yes(24) No(0)
• just see A G & I are respectively for american german and indian
  well now no 2I be together so
  arrangement for A'S & G'S taking together are 6!
  and there is 7 place b/w them for I'S
  I'S arrangement for sitting is 7!
  so prob=7!6!/13!
• 9 years agoHelpfull: Yes(4) No(0)
• b)7!6!/13!
• 9 years agoHelpfull: Yes(1) No(0)
• 7!6!/13! ... all the indians must be separated allowing 6 blank chairs among them, which is to be filled by americans & germans.. hence..
• 9 years agoHelpfull: Yes(1) No(0)