Question

in a class consisting of 70% boys, 20%of boys and 10% of girls play chess. a student is chosen at random from the class and found to be a chess player. find the probability that selected student is a girl​

Answer 1

Answer:

18/95

Step-by-step explanation:

Given that the number of boys and girls in a class is as follows:

Number of boys = 11

Number of girls = 9

Then we conclude that the total number of students in the class= 20 students.

Then, the probability of choosing a girl = number of girls. total number of students in the class = 9/20

The probability of choosing the 2nd girl = number of remaining girls / number of all students minus the chosen girl = 8/19

Then , the probability of choosing two girls is :

The probability of choosing 2 girls = 9/20 *  8 /19

                                                = 72/380

                                                = 18/ 95

Then the probability of choosing 2 girls = 18/95