Permutations And Combinations Question 312

Question: There are three men and seven women taking a dance class. Number of different ways in which each man is paired with a woman partner, and the four remaining women are paired into two pairs each of two is

Options:

A) 105

B) 315

C) 630

D) 450

Show Answer

Answer:

Correct Answer: C

Solution:

  • [c] $ 10<\begin{matrix} 3m \\ 7w \\ \end{matrix}3 $ Women can be selected in $ ^{7}C_3 $ ways and can be paired with 3 men in 3! Ways. Remaining 4 women can be grouped into two couples in $ 4!/(2!\cdot 2!\cdot 2!)=3. $ Therefore, total $ {{=}^{7}}C_3.3!.3=630 $ .