Q67 / 150 · MHT CET 2009 · Mathematics
From a group of 8 boys and 3 girls, a commitee of 5 members to be formed. Find the probability that 2 particular girls are included in the committe is
- A$\frac{4}{11}$
- Correct answerB$\frac{2}{11}$
- C$\frac{6}{11}$
- D$\frac{8}{11}$
Solution
Total $\quad$ number $\quad$ of $\quad$ ways $={ }^{8} \mathrm{C}_{2}{ }^{3} \mathrm{C}_{3}+{ }^{8} \mathrm{C}_{3}{ }^{3} \mathrm{C}_{2}+{ }^{8} \mathrm{C}_{4}{ }^{3} \mathrm{C}_{1}+{ }^{8} \mathrm{C}_{5}{ }^{3} \mathrm{C}_{0}$
$=28 \times 1+56 \times 3+70 \times 3+56 \times 1$
$=462$
Number of ways in which 2 particular girls are included ${ }^{9} C_{3}=84$
$\therefore$ Required probability $=\frac{84}{462}=\frac{2}{11}$
Hence, the correct answer is option: 'B'.