There are n persons sitting in a row, two of them are selected at random. The probability that two selected persons are not together is: |
$\frac{2}{n}$ $1-\frac{2}{n}$ $\frac{n(n-1)}{(n+1)(n+2)}$ None of these |
$1-\frac{2}{n}$ |
P(selected person not together) = 1 – P(selected person together) = $1-\frac{n-1}{{^nC}_2}=1-\frac{2}{n}$ |