- Home
- Standard 11
- Mathematics
14.Probability
medium
A committee consists of $9$ experts taken from three institutions $A, B$ and $C$, of which $2$ are from $A, 3$ from $B$ and $4$ from $C$. If three experts resign, then the probability that they belong to different institutions is
A
$\frac{1}{{729}}$
B
$\frac{1}{{24}}$
C
$\frac{1}{{21}}$
D
$\frac{2}{7}$
Solution
(d) Required probability $ = \frac{{{}^2{C_1} \times {}^3{C_1} \times {}^4{C_1}}}{{{}^9{C_3}}} $
$= \frac{{2 \times 3 \times 4}}{{\left( {\frac{{9 \times 8 \times 7}}{{3 \times 2}}} \right)}} = \frac{2}{7}$.
Standard 11
Mathematics
Similar Questions
normal