Amit Kumar

The number of ways that a mixed doubles tennis game can be arranged from 7 married couples if no husband and wife play on the same game.

Hi, My answer for the question: for question The number of ways that a mixed doubles tennis game can be arranged from 7 married couples if no husband and wife play on the same game. Ans: In mixed double we have four position. 1. First position of a man can be filled with 7 ways as we can select any man out of seven. --- 7 2. Second position we need to select woman and we can select any 6 woman out of seven as we can not select husband of the person at First position. -- 6 3. In third position we can select any one person out of 5. Why because we should have any couple playing the game any of the side. After first position we are remaining with six man, out of which one would be the husband of second position woman, so we have 5 ways for third position. -- 5 4. For fourth position we can select any one woman out of 4. As after second position is filled we are left with five woman. We can select the woman who is the wife of third position Man. So we are left with 4 woman at fourth position. --4 So total possible arrangement would be all combination of these four position : 7*6*5*4=840. Thanks, Amit