Find the probability of a 4 turning uppermost at least once in two tosses of a fair die? I am a bit confused about what this questions about.


Is it looking for the possibilities of getting 4 at least once in the toss, 
or
The possibilities to get 4 as the highest number of the two toss at least once?

A = {{1,4},{2,4},{3,4},{4,4},{5,4},{6,4},{4,1},{4,2},{4,3},{4,5},{4,6}}

B = {{1,4},{2,4},{3,4},{4,4},{4,1},{4,2},{4,3},}
From the context of "at least once in two tosses", I would interpret "uppermost" to mean "shows on the upper face of".



Your alternative interpretation is not an "at least once" type of event, it is more of a "does or does not" kind of thing.
S = {1,2,3,4,5,6,1,2,3,4,5,6}

n(S) = 12

A is the event of getting 4

A = {4,4}
n(A) = 2

P(A) = n(A)/n(S)
         = 2/12
         = 1/6

Therefore, the probability of getting 4 atleast once in two tosses of a fair die is 1/6