£ represents 29 students in class
B represents students who have a brother
S represents students who have a sister
a) One student from the class is chosen at random. What is the probability that the student has a sister?
b)One of the students who has a brother is chosen at random. What is the probability that this student has a sister?

a) One student from the class is chosen at random. What is the probability that the student has a sister?

S/£

b)One of the students who has a brother is chosen at random. What is the probability that this student has a sister?

BS/£²

Step-by-step explanation:

In the question, we are given the following values:

£ represents 29 students in class = Total number of students in the class.

B represents students who have a brother

S represents students who have a sister

The formula for probability = Number of events ÷ Number of possible outcomes.

a) One student from the class is chosen at random. What is the probability that the student has a sister?

Number of events = Number of students that have a sister = S

Number of possible outcomes = £ represents 29 students in class

The probability that the student has a sister = S/£

b)One of the students who has a brother is chosen at random. What is the probability that this student has a sister?

This is calculated as

The Probability of Students that have a brother and a sister = Probability of students that have a brother × Probability of student that have a sister.

Number of students that have a brother = B

Number of students that have a sister = S

The Probability of Students that have a brother and a sister = B/£ × S/£

= BS/£²

whatever you can spend with $11.53 or under.

step-by-step explanation:

20 - 8.47 = 11.53. take away the money he used for lunch from the starting amount of 20.

answer: i don't understand. what are the options

step-by-step explanation: