Question

In a class of students, the following data table summarizes how many students have a

brother or a sister. What is the probability that a student who has a brother also has a
sister?
Has a brother | Does not have a brother
Has a sister
6
2
Does not have a sister
8
13​

Answer 1

`Probability = (6)/(29)`

Explanation:

Given

------------------------------Has a brother | Does not have a brother

Has a sister --------------------------- 6 ----------------- 8

Does not have a sister -----------2 ------------------ 13

Required

Probability of having a sister and a brother

First, the total number of students has to be calculated;

Total = 6 + 2+ 8 + 13

Total = 29

Number of students that have a sister and a brother is represented with data in row 1 and column 1 i.e. 6

At this point, the probability can then be calculated;

Probability = Number of students that have a sister and a brother divided by Total number of students

`Probability = (6)/(29)`