Necessity

　Necessity
　A man will pay $2 for a $1 item that he needs.
　A woman will pay $1 for a $2 item that she doesn’t need.

　Romance Mathematics
　Smart man + smart woman = romance
　Smart man + dumb woman = affair
　Dumb man + smart woman = marriage
　Dumb man + dumb woman = pregnancy

　A flight attendant
　A flight attendant asked a passenger if he would like dinner.
　“What are my choices?”
　“Yes or no”