Card determination:-
Mary selects a card from a pack of 52 playing cards. John attempts to determine the card by asking a series of yes-no questions that Mary answers correctly. In general, how many questions must John ask to be sure he can determine the card? What questions should he ask to minimize the average number of questions that are required?
(Hint: the first question might be, "Is the card black or red?" Do not try to work out the Huffman code. Just think about how to ask the questions.)