Four men and four women (including two particular women, and ) are to be seated in a row so that no two men sit next to each other and , are not seated next to each other. The number of ways is
Answer and explanation
Correct answer: A. 2592
- Step 1: Seat the women first in a row in ways. This creates available gaps (ends and between women) to seat the men such that no two men are adjacent.
- Step 2: Choose and arrange men in of these gaps in ways. The total number of arrangements with no two men adjacent is .
- Step 3: Subtract the forbidden cases where and sit next to each other. Treat or as a single block ( arrangements of women units), creating gaps for men. The men must fill all gaps with no man between and in ways, giving invalid arrangements. Thus, valid ways .
Answer
2592.
Practise more Permutations and combinations.
Free questions with an explanation for every one, and full timed WBJEE mock tests.
More Permutations and combinations questions
- In how many ways can a committee of be chosen from people?
- In how many ways can a committee of be chosen from people?
- In how many ways can a committee of be chosen from people?
- How many different arrangements of distinct books are possible on a shelf?
- In how many ways can a committee of be chosen from people?
- How many different arrangements of distinct books are possible on a shelf?