Probability Ques 37
Question-
Directions : The following line graph shows the details of male and female students in five different groups. Consider the following graph and answer the questions given below:
Four students are selected from group $B$ one by one without replacement. What is the probability that they are alternatively of different genders?
(1) $\frac{12}{85}$
(2) $\frac{14}{99}$
(3) $\frac{15}{79}$
(4) $\frac{13}{88}$
(5) $\frac{11}{71}$
Show Answer
Correct Answer: (2)
Solution: (2)
Required probability $=\left(\left(\frac{5}{12}\right) \times\left(\frac{7}{11}\right) \times\left(\frac{4}{10}\right) \times\left(\frac{6}{9}\right)\right)$
$+\left(\left(\frac{7}{12}\right) \times\left(\frac{5}{11}\right) \times\left(\frac{6}{10}\right) \times\left(\frac{4}{9}\right)\right)$ $=\frac{7}{99}+\frac{7}{99}=\frac{14}{99}$
BETA
