Answer:
Mr. Smith has two children. If the older child is a boy, what are the odds that the other child is also a boy?
There are 20 birds in a tree. A man comes and shoots one of the birds. How many birds are left?
Why can't Kevin, who is now living in Canada, not be buried in the USA?
An archaeologist unearths a coin bearing the inscription "57BC". How does he instantly know that it's a forgery?
A man goes upstairs to grab his time machine. He walks downstairs then goes back in time 200 years. Why did he go downstairs?
What is always coming but never arrives?