Question
Tue June 19, 2012 By: Sonali

Two dice ,one white and one red ,are rolled together.Find the probability of getting (i)asum of 6(ii)two different digits(iii)adifference of 1

Expert Reply
Tue June 19, 2012
Total number of possible outcomes can be: 6 x 6 =36
as each dice can show 6 faces each
 
(i)  A sum of 6 ca be obtained in following ways:
          White    Red
             1          5
             2          4
             3          3
             4          2
             5          1
since both dice are indistinguishable hence we have to take 2  -  4 and 4   -   2 and other similar case independently.
thus porbability is : 5/36
 
(ii)        it is similar to picking up two numbers from 1 to 6 with out any repetition i.e. 6 P2 = 6!/4!=30
hence probability = 30/36
 
(iii) it can be done as:
        white dice can assume 5 values and red dice will assume 5 corresponding values and then the same configuration in reverse
i.e red can have 3 then white can have 4 and vice versa i.e red 4 and white 3
thus total case = 2 x 5 =10
hence probability = 10/36
Home Work Help