Question

A standard deck of cards contains 52 cards. one card is selected from the deck. ?(a) compute the probability of randomly selecting aa heartheart or spadespade. ?(b) compute the probability of randomly selecting aa heartheart or spadespade or clubclub. ?(c) compute the probability of randomly selecting aa twotwo or diamonddiamond.

Answer 1

Let
P(h)= probability of selecting heart = 13/52= 1/4
similarly
P(s)= probability of selecting spade =1/4
P(c)= probability of selecting club =1/4
P(d)= probability of selecting diamond =1/4

a)

P(h or s)= P(h)+P(s)= 1/4+1/4=2/4=1/2=0.5

b)

P(h or s or c)=P(h)+P(s)+P(c)=1/4+1/4+1/4=3/4=0.75

c) 

P(2 or a diamond)=n(2heart, 2spade,2club,13 diamonds)/total number of cards

=(1+1+1+13)/52=16/52=4/13=0.3

or we could solve it as follows:

P(2 or a diamond)=P(2)+P(diamond)-P(2diamond)=4/52  +  13/52  + 1/52  = (4+13-1)/52=16/52=0.3