Coins whose faces are marked 1 2 are thrown Find the probability of getting a total of 5 ........

Explanation:

Let A be the event of total of 5, then 

 A={(2,2,1)}

 n(A)=1                           

Sample space contain total possibility=2³

 =8

 Hence n(T)=8

 So P (A)=n(A)/n(T)

 =1/8