A pack of playing cards was found to contain only 51 cards. If the first 13 cards which are examined are all red, then the probability thatthe missing card is black, is:
Total number of cards = 52
Number of lost cards = 1
13 cards are surley red therfore, from the remaining 39 cards 26 are black and 13 are red.
So probabilityof lost card being black $=\frac{(261)}{(391)}=\frac{26}{39}=\frac{2}{3}$
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