A committee of five is to be chosen from a group of 9 people. probability that a certain married cou

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14.Probability

easy

A committee of five is to be chosen from a group of $9$ people. The probability that a certain married couple will either serve together or not at all, is

A

$\frac{1}{2}$

B

$\frac{5}{9}$

C

$\frac{4}{9}$

D

$\frac{2}{9}$

Solution

(c) Required probability $ = \frac{{{}^7{C_3}}}{{{}^9{C_5}}} + \frac{{{}^7{C_5}}}{{{}^9{C_5}}} = \frac{{56}}{{126}} = \frac{4}{9}.$

Standard 11

Mathematics

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