Question

A die is thrown twice. What is the probability that 

(i) 5 will not come up either Urne? 

(ii) 5 will come up at least once? 

[Hint: Throwing a die twice and throwing two dice simultaneously are treated as the same experiment.]

Answer 1

The possibility that one die is thrown:

n(S) = 6 × 6 = 36

(i) 5 will come up either time:

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

∴ Possible events = 11.

∴ Probability that 5 will not come up either time : 

36 – 11 = 25 n(E) = 25

(ii) Possibility that 5 will come up at least ones: 11 

∴ n(E) = 11