When two dice are thrown what is the probability that the sum is 8.

We assume that each face of the dice number is numbered
serially from 1 ,2,3,4,5,6.

When the two dice are thrown ,
one if the 36 ordered pairs can occur:

(1 ,1) ,
(1,2)......(1,6),

(2,1) , (2, 2)
....(2,6),

(3,1) , (3,2)
......(3,6)

................................

...............................

(6,1)
, (6,2) ........(6,6)

So a total of 8 can occur in follwing
pairs:

(2 ,6) , (3,5) ,(4,4) , (5 , 3) ,(6,
2)

So there are 5 pairs of occurence of dice showing up
faces when the serial number on the faces adds up 8, as against 36 possible pairs of
numbers showing up.

So the probability of the event of
showing the sum of the numbers on the face equal to 8 is
5/36.