Question

# It is required to seat 5 men and 4 women in a row so that the women occupy the even places. How many such arrangements are possible?

Thus, the places for the women are fixed, thus the total number of arrangements is 4! (which is $^{4}{{P}_{4}}$).
Similarly, due to the women’s places getting fixed, men’s places automatically fixed, thus the total number of arrangements is 5! (which is $^{5}{{P}_{5}}$). Now, combining these results, we have a total number of combinations of 4!$\times$5!=2880.