Here are a few rhetorical questions that actually deserve an answer but please dont analyse them too closely.
The council snow plough driver........How does he get to work in a morning?
Before golf balls were invented...........How were hailstones measured?
The guy who invented the drawing board................What did he go back to before he got it right?
How can you ever get any more seedlees grapes?
There must be loads more of these, any suggestions?