I have three slips of paper. On one of them I have written the letter A and on the other two I have written the letter F. The papers are face down so only I know what

is written on each slip. I ask you to choose one of these slips, as this will determine

your letter grade for the course. Yikes! You make your choice, but before I reveal your

fate, I turn over one of the other slips and reveal an F (whew!), and then offer you the

choice to either keep your slip or exchange it for the other yet-to-be-revealed slip. The

question is... do you "keep" or "exchange"?

[8 points] Explain clearly using probability whether it is in your best interest to keep

your slip, exchange it for the other unrevealed slip, or whether it makes no difference

to keep or exchange.