Question

can anyone help me with this ??

Answer 1

Answer:

A. 336

B. Arranging 3 people in 8 chairs.

C. 42

B. Arranging 2 people in 7 chairs.

Step-by-step explanation:

A.

$P(n, r) = P(8, 3)$

Formula for Permutation is given as:

$P(n, r) = \dfrac{n!}{(n-r)!}$

Putting the value of $n$ = 8 and $r =3$ , we get:

$P(8, 3) = \dfrac{8!}{(8-3)!} \\\Rightarrow \dfrac{8\times 7 \times 6 \times 5\times 4 \times 3 \times 2\times 1}{5\times 4 \times 3\times 2\times 1}\\\Rightarrow 8\times 7 \times 6 \\\Rightarrow 336$

B. Real world situation for part A:

Arranging 3 people on 8 chairs.

First person has 8 options.

Second person has 7 options.

Third person has 6 options.

C.

$P(n, r) = P(7, 2)$

Formula for Permutation is given as:

$P(n, r) = \dfrac{n!}{(n-r)!}$

Putting the value of $n$ = 7 and $r$ = 2 , we get:

$P(7, 2) = \dfrac{7!}{(7-2)!} \\\Rightarrow \dfrac{7 \times 6 \times 5\times 4 \times 3 \times 2\times 1}{5\times 4 \times 3\times 2\times 1}\\\Rightarrow 7 \times 6 \\\Rightarrow 42$

D.  Real world situation for part AC:

Arranging 2 people on 7 chairs.

First person has 7 options.

Second person has 6 options.