Question
If two natural numbers $r$ and $s$ are drawn one at a time, without replacement from the set $S = \{ 1,2,3, \ldots n\}$, then find $P(r \le p/s \le p)$, where $p \in S$.
Probability — Class 12 Maths Solution
Step-by-step Solution
Set $S = \{ 1,2,3, \ldots ,n\}$
$\therefore$ $P(r \le p/s \le p) = \frac{{P(p \cap S)}}{{P(S)}}$
$= \frac{{p - 1}}{n} \times \frac{n}{{n - 1}} = \frac{{p - 1}}{{n - 1}}$
NCERT & Exemplar solution for CBSE Class 12 Mathematics, Probability. Curated by Sachin Sharma. Free for all students.