In how many ways can 8 Indians and, 4 American and 4 Englishmen can be seated in a row so that all person of the same nationality sit together?  Choices.
A) 4!*3!  B) 3!*8!*4!*4!  C) 3!*8!  D) 5!*3!  E) 8!*4!
Taking all person of same nationality as one person, then we will have only three people.   These three person can be arranged themselves in 3! Ways.   8 Indians can be arranged themselves in 8! Way.   4 American can be arranged themselves in 4! Ways.   4 Englishman can be arranged themselves in 4! Ways.   Hence, required number of ways = 3!*8!*4!*4! Ways.   Ans: 3!*8!*4!*4!
<result>B</result>
In how many ways can 8 Indians and, 4 American and 4 Englishmen can be seated in a row so that all person of the same nationality sit together?