Question

Two dice, one white and one red are rolled together .Find the probability of getting 

(ii) two different digits

Answer 1

lf two dice are rolled then the possible outcomes are : 

(1, 1), (1, 2), (1, 3), (1, 4), (1, 5), (1, 6) 
(2, 1), (2, 2), (2, 3), (2, 4), (2, 5), (2, 6) 
(3, 1), (3, 2), (3, 3), (3, 4), (3, 5), (3, 6) 
(4, 1), (4, 2), (4, 3), (4, 4), ( 4, 5), ( 4, 6) 
(5, 1), (5, 2), (5, 3), (5, 4), (5, 5), (5, 6) 
(6, 1), (6, 2), (6, 3), (6, 4), (6, 5), (6, 6) 

So the total number of outcomes = 36 

 two different digits 

Here we use the following formula : 

P(Two different digits) = 1- P(both digits are same) 

Now favorable outcomes for both digits same are: (1,1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6) 

So the number of possible outcomes for both digits same = 6 

Thus, P(Two different digits) = `1- 6/36 = 5/6`