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Three student representatives, a president, a secretary, and a treasurer, are to be chosen from a group of five students: Andrew, Brenda, Chad, Dorothy, and Eric. In how many different ways can the representatives be chosen if the president must be a woman and the secretary and treasurer must be menNote that Brenda and Dorothy are women while Andrew, Chad, and Eric are men

User Dave Collins
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26 votes
26 votes
Answer:

Number of ways that the representative can be chosen = 12

Step-by-step explanation:

The number of women = 2

The number of men = 3

Since the president must be a woman

Number of ways of choosing the president = 2C1


\begin{gathered} 2C1=\text{ }(2!)/((2-1)!1!) \\ 2C1=2 \end{gathered}

Number of ways of choosing the president = 2

The secretary and treasurer must be men

Let us first choose the secretary out of all the three men

Number of ways of choosing the secretary = 3C1


\begin{gathered} 3C1=\text{ }(3!)/((3-1)!1!) \\ 3C1=\text{ }(3!)/(2!) \\ 3C1\text{ = }(3*2*1)/(2*1) \\ 3C1=\text{ 3} \end{gathered}

Number of ways of choosing the secretary = 3

After the secretary has been selected, there are 2 men left

Number of ways of selecting the treasurer = 2C1

Number of ways of choosing the treasurer = 2

Number of ways that the representative can be chosen = 2 x 3 x 2

Number of ways that the representative can be chosen = 12

User Abl
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