If an unbiased dice is rolled thrice, then the probability of getting a greater number in the ith roll than the number obtained in the (i - 1)th roll, i = 2, 3, is equal to
- 5/54
- 2/54
- 1/54
- 3/54
Answer
(1) 5/54
Solution
We need x1 < x2 < x3. Any 3 different numbers out of 6 can be arranged in increasing order in exactly one way, so favourable cases = 6C3 = 20.
Total cases = 63 = 216
Probability = 20216 = 554
Answer: (1)