Question #59d64

2 Answers
Jan 25, 2018

The probability is 30.8%

Explanation:

There are 52 cards in all, and 13 are spades. In addition, 4 are aces, but one of these aces is also a spade! We won't count it twice.

So, in total, we have 13 + 3 = 16 cards that are either spade or ace (including one that is both spade and ace, which I assume is to be included in the sample of "successful choices").

Probability = (successful events) / (all events) = #16 -: 52 = 0.308# or 30.8 %

Note: If "either a spade or an ace" is not meant to include the card that is both spade and ace, then reduce the number of successful events to 15.

Jan 25, 2018

#4/13#

Explanation:

#P(AuuB)=P(A)+P(B)-P(AnnB)#

Let#" "A=#a spade#=>P(A)=13/52#

#B=#an Ace#=>P(B)=4/52#

#"also "P(AnnB)=1/52#
( ie the probability of the ace of spades)

#P(AuuB)=13/52+4/52-1/52#

#=16/52=4/13#