Multiple choice

A group consists of 4 couples in which each of the 4 persons have one wife each. In how many ways could they be arranged in a straight line such that the men and women occupy alternate positions?

  1. 1152

  2. 1278

  3. 1296

  4. 1176

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Arrange 4 men in 4! ways. Arrange 4 women in 4! ways. There are two patterns: MWMWMWMW or WMWMWMWM. Total = 2 * 4! * 4! = 2 * 24 * 24 = 1152.

AI explanation

For the 4 men and 4 women to sit in alternate positions, the row must either start with a man or start with a woman. If the row starts with a man, the 4 men can be arranged in the 4 odd positions in 4 factorial ways, and the 4 women can be arranged in the 4 even positions in 4 factorial ways, giving 4 factorial times 4 factorial arrangements. Because either gender can start the row, we multiply this by 2, resulting in 2 times 24 times 24, which is 1152. The result is 1152.