Postmaster general admits he doesn't know what it costs to mail a postcard

What does it cost to mail a postcard? Don't ask the guy in charge of the United States Postal Service.Postmaster General Louis DeJoy testified before Congress on Monday to face questions from lawmakers about controversial changes at USPS. But when it was Rep. Katie Porter's (D-Calif.) turn for questions, she decided to open with a bit of a pop quiz about Postal Service prices.For one, she wanted to know, what does a first class postage stamp cost? Fifty-five cents, he answered. But how much does