£ 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

d. millimeters per hour.

step-by-step explanation:

we are given that,

carlo used a rain gauge to measure the amount of water his lawn is receiving from the sprinklers.

since, according to the options, we see that,

water cannot be measured by 'miles per hour', 'meters per second' and 'grams per seconds'.

we get that, the water can be measured by 'millimeters per hour'.

hence, the appropriate rate for describing the amount of water is 'millimeters per hour'.

f is the midpoint of