SOLUTION: Is it D? I want to check my answer. A teacher asked students in his class if they had any brothers or sisters. The results are shown below. What is the chance of randomly select

Algebra.Com
Question 1161046: Is it D? I want to check my answer.
A teacher asked students in his class if they had any brothers or sisters. The results are shown below. What is the chance of randomly selecting someone from this group with a brother given that they have a sister?
P(Brother|Sister)
A. 5/12
B. 5/17
C. 5/9
D. 5/14

The Venn diagram for the question and the question itself are provided in the link here: https://i.imgur.com/Y4MOmRK.png

Answer by ikleyn(52781)   (Show Source): You can put this solution on YOUR website!
.

The diagram under the link shows, that there are 12 students in the class who have sister/sisters.


We can consider these 12 students as the population's part described by this fragment of the condition


           +------------------------------------+
           |  "given that they have a sister".  |
           +------------------------------------+


Of these 12 students, 5 have a brother/brothers.


Therefore, the probability under the problem's question is  .


The  ANSWER  is option A.

Solved.

-------------------

An important post-solution note.

    The important part is that the brothers or sisters can be not at / (or from) the given class.

    They (the sisters and the brothers) can be from totally different sets outside the class.



    Also, it is important to understand that the circles "brothers" and "sisters" on Venn  diagram DO NOT REPRESENT the girls or the boys.

    They represent partial populations of the class united according to the principle "has or not has this feature".


    It is similar to as if the students in the class were wearing special badges "have a brother", or "have a sister", OR BOTH (!)


If you understand all of that,  it means that you understand the problem  ADEQUATELY.


This problem  TEACHES  YOU  to understand the given description adequately.



RELATED QUESTIONS

Hello, my name is Cody McCullough. I need help witha problem that I am helping my brother (answered by acerX)
Is it B? I want to check my answer. Consider the following table with information... (answered by MathLover1)
Hi, So my friends have been going crazy over a problem. I'm not sure of the exact... (answered by MathLover1)
i am supposed to identify like terms but i don't understand it my problem is... (answered by rfer,ankor@dixie-net.com)
Is C correct? I want to check my answers. Jarvis has the following averages in his... (answered by MathLover1)
This may seem like a crazy question, but every book I have consulted gives a vague... (answered by shree840,richard1234)
Is it D? I want to check my answer. The following shows a corn maze for participants... (answered by jim_thompson5910)
Mrs. Jones surveys her class. 75% students have brothers. 82% have sisters. 65% have... (answered by ewatrrr)
Is it D? I want to check my answer. James currently has $215 in a savings account.... (answered by MathLover1,MathTherapy)