Step-by-step explanation:
to prove that Andy is innocent, let's analyse the given information step by step:
1. A crime is committed and no one other than Andy, Betty, or charlie is involved.
This means that the person who committed the crime is either Andy, Betty, or charlie.
2. either Betty or charlie committed the crime.
based in this statement, we know that either Betty or charlie is the guilty party. it means that Andy is not the only person who could have Committed the crime.
3. If Betty is guilty then Andy is innocent.
according to this statement, if Betty is the one who committed the crime, then Andy is innocent.this means that If Betty is guilty, Andy cannot be the guilty party.
4. either charlie or Andy is innocent.
this statement tells us that either charlie or Andy is innocent. it doesn't necessarily mean the both of them are innocent, but at least one of them is.
from the given information, we can deduce that Betty is the only person who could have Committed the crime since either Betty or charlie is guilty.
however If Betty is guilty then Andy is innocent. therefore Andy is innocent.
in summary:
based on statement 2, Betty or charlie committed the crime.
statement 3, if Betty is guilty then Andy is innocent
since Betty is the only person who could have Committed the crime, Andy is innocent.
therefore Andy is proven to be innocent based on the given information.