SOLUTION: In reviewing my stats and probability I've been doing practice SAT questions. This is one I've encountered that seems inaccurate but I am not certain. Here goes:
There is a clas
Question 734926: In reviewing my stats and probability I've been doing practice SAT questions. This is one I've encountered that seems inaccurate but I am not certain. Here goes:
There is a class of 20 girls. 15 have brown hair and 12 have brown eyes. If a random girl with brown hair is selected, what is the chance she also has brown eyes?
Now, I have approached this as follows:
P(BH) = 3/4
P(BE) = 3/5
P(BH and BE) = 9/20
Thus of the 15 girls with brown hair 9/20ths of them have brown eyes too. Or:
15 * 9/20 = 27/4 = 6.75 -> aprox. 7/15 chance a girl with brown hair will have brown eyes also.
The app I'm using gives an explanation that says only 7 girls have brown hair and brown eyes and this can be easily shown with a venn diagram. But in constructing a venn diagram I feel that there is not enough info presented to determine this easily. What am I missing? Or is the question flawed?
Thanks in advance!! Answer by lynnlo(4176) (Show Source): You can put this solution on YOUR website!