Evaluate fraction numerator P presubscript 4 subscript 2 times P presubscript 6 subscript 1 over denominator P presubscript 18 subscript 3 end fraction.A.1 over 68 B.begin display style 4 over 5 end style C.begin display style 3 over 68 end style D.begin display style 2 over 3 end style

Evaluate fraction numerator P presubscript 4 subscript 2 times P presubscript 6 subscript 1 over denominator P presubscript 18 subscript 3 end fractionA1 over 6 class=

Respuesta :

Given:

[tex]\frac{4P_2\cdot6P_1}{18P_3}[/tex]

Required:

We need to evaluate the given expression.

Explanation:

Consider the formula.

[tex]nP_r=\frac{n!}{(n-r)!}[/tex]

Use this formula to evaluate the given expression.

[tex]\frac{4P_2\cdot6P_1}{18P_3}=\frac{\frac{4!}{(4-2)!}\cdot\frac{6!}{(6-1)!}}{\frac{18!}{(18-3)!}}[/tex]

[tex]Use\text{ }\frac{\frac{a}{b}}{\frac{c}{d}}=\frac{a}{b}\cdot\frac{d}{c}.[/tex]

[tex]\frac{4P_2\cdot6P_1}{18P_3}=\frac{4!}{(4-2)!}\cdot\frac{6!}{(6-1)!}\cdot\frac{(18-3)!}{18!}[/tex]

[tex]\frac{4P_2\cdot6P_1}{18P_3}=\frac{4!}{2!}\cdot\frac{6!}{5!}\cdot\frac{15!}{18!}[/tex]

[tex]\frac{4P_2\cdot6P_1}{18P_3}=\frac{4\times3\times2!}{2!}\cdot\frac{6\times5!}{5!}\cdot\frac{15!}{18\times17\times16\times15!}[/tex]

Cancel out the common factorials.

[tex]\frac{4P_2\cdot6P_1}{18P_3}=\frac{4\times3}{1}\cdot\frac{6}{1}\cdot\frac{1}{18\times17\times16}[/tex]

[tex]\frac{4P_2\cdot6P_1}{18P_3}=\frac{4\times3\times6}{18\times17\times16}[/tex]

[tex]\frac{4P_2\cdot6P_1}{18P_3}=\frac{1\times18}{18\times17\times4}[/tex]

[tex]\frac{4P_2\cdot6P_1}{18P_3}=\frac{1}{17\times4}[/tex]

[tex]\frac{4P_2\cdot6P_1}{18P_3}=\frac{1}{68}[/tex]

Final answer:

[tex]\frac{4P_2\cdot6P_1}{18P_3}=\frac{1}{68}[/tex]