Suppose that a study is being done on all families with one, two, or three children. Let the outcomes of the study be the genders of the children in descending order of their age.
A. List sample space: $M$ = Male $F$ = Female $$ \{M, F, MF, MM, FM, FF, MMM, MMF, MFM, MFF, FFF, FFM, FMF, FMM\} $$
B. Let $A$ be the event that the eldest child is a girl, and let $B$ be the event that exactly two children are girls. List the sample points in $A$ and $B$. Are $A$ and $B$ mutually exclusive? Why or why not?
Sample points $\{FF,FFM,FMF\}$
So they aren't mutually exclusive. But I don't know how to explain why or why not? Can somebody help me on this?