单选题
If two cards are drawn randomly out of a standard deck of 52 playing cards, what is the probability that both are aces? Write your answer as a fraction.
【正确答案】
【答案解析】.There are four aces in a standard deck of 52 cards, so the probability of randomly drawing out an ace is 
. If that is done successfully, there will be 51 cards left, three of which will be aces. The probability that a second ace is drawn out will thus be 
. The probability of randomly drawing out two aces is thus 
. Any fraction that reduces to this is also correct.
. If that is done successfully, there will be 51 cards left, three of which will be aces. The probability that a second ace is drawn out will thus be . The probability of randomly drawing out two aces is thus . Any fraction that reduces to this is also correct.