In a high school having equal number of boy students and girl students...
Method 1
Given :
50% of the total students are boys so probability of boys P(B)= 1/2
50% of the total students are girls so probability of girls P(G)= 1/2
75% students studies science, so probability of student studies science, P(S)=3/4
25% students studies commerce, so probability of student studies commerce, P(C)=1/4
Given commerce students are two times more likely to be a boy than are science students.
Let the probability that a science student is boy i.e.,
From total probability theorem, the probability of a selected student to be a boy is
Hence probability of a selected commerce student is a girl,
Probability of randomly selected girl studies commerce is given as
Hence, information in knowing that a randomly selected girl studies commerce is given as
Hence, the amount of information gained in knowing the a randomly selected girl student studies commerce is 3.32 bits.
Method 2 :
Let total number of students is 100.
Given, there are equal number of boys and girl students.
∴ Total number of boys = 50
Total number of girls = 50
Given commerce students are two times more likely to be a boy than are science students.
Let Probability of science student to be boy = p.
∴ Probability of science students to be girl = 1− p
p is defined as,
∴ Number of boys in science = Bs= 75p
∴ Number of girls in science = 75− 75 p
Number of boys in commerce = 50− 75 p
Number of girls in commerce = 25− (50 − 75 p) = 75 p− 25
∴ Probability that if a randomly selected student out of 100 students is a girl then she studies commerce is,
Hence, Information in knowing that a randomly selected student is girl and studies commerce is
Hence, the amount of information gained in knowing the a randomly selected girl student studies commerce is 3.32 bits.
Question_Type: 4