help will probablity

Question

  one card is drawn from a deck of 52.  what is the probability that it is (written as fraction)

 

a.  a diamond  ?

 

b.  a king  ?

 

c.  an ace or king  ?

 

 

I have:

 

a.  P(A) = P(1) + P(2) + P(3) + P(4) + P(5) + P(6) +P(7) + P(8) + P(9) + P(10) + P(11) + P(12) + P(13) =  1/13

 

b.  same as a  =  1/13

 

c.  P(A) = 1/26 + 1/26 + 1/26 + 1/26 + 1/26 + 1/26 + 1/26 + 1/26 + 1/26+ 1/26+ 1/26 + 1/26 + 1/26 = 13/26  = 1/3

 

 

thanks

Answer 1

There are 52 cards in a deck:

 

a) 13 of the 52 cards are diamonds.  The probability of drawing a diamond is 13/52 = 1/4.

 

b)  4 of the 52 cards in a deck are kings.  The probability of drawing a king is 4/52 = 1/13.

 

c)  There are 4 aces and 4 kings in a deck.  The probability of drawing a king or an ace is 4/52 + 4/52 = 8/52 = 2/13