6 men and 4 women are to be seated in row so that no two women sit together. The number of ways they can be seated is ________.
Hint 1: Use the gap method: arrange the 6 men first in ways.
Hint 2: Count the number of gaps created around the 6 men, which is 7 slots.
Hint 3: Arrange the 4 women in these 7 slots in ways, and multiply the two counts.
Step 1 (Arrange the Men): First, we seat the 6 men in a row. The number of ways to arrange 6 distinct men is:
Step 2 (Identify Gaps for Women): To ensure no two women sit together, we place the 4 women in the gaps between the men (and at the ends). For 6 men seated in a row:
There are exactly available gaps/slots.
Step 3 (Arrange the Women in Gaps): We choose 4 distinct gaps out of 7 for the 4 women and arrange them. The number of ways is given by permutations :
Step 4 (Multiply the Permutations): Total ways = (Ways to arrange men) (Ways to place women):
Step 5 (Conclusion): The number of seating arrangements is exactly 604800.
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