Question

In a dinner party there are 10 Indians, 5 Americans and 5 Englishmeň. In how many ways can they be arranged
in a row so that all persons of the same nationality sit together ?​

Answer 1

Answer:

consider Indians as a single entity. And Americans as another entity and Englishmen as third entity. Then we can arrange three of them in 3! ways.

the Indians can be arranged among themselves in 10! ways and Americans among themselves in 5! ways and Englishmen in 5! ways.

so, number of ways= 3! * 10!* 5!*5! ways