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JEE Mains · Maths · STD 11 - 14. probability

If an unbiased dice is rolled thrice, then the probability of getting a greater number in the \(i^{\text {th }}\) roll than the number obtained in the \((i-1)^{\text {th }}\) roll, \(i=2,3\), is equal to :

  1. A \(3 / 54\)
  2. B  \(2 / 54\)
  3. C \(5 / 54\)
  4. D  \(1 / 54\)
Verified Solution

Answer & Solution

Correct Answer

(C) \(5 / 54\)

Step-by-step Solution

Detailed explanation

Favourable cases \(={ }^6 \mathrm{C}_3\) Total out comes \(=6^3\) Probability of getting greater number than previous \(\text { one }=\frac{{ }^6 \mathrm{C}_3}{\mathrm{r}^3}=\frac{20}{216}=\frac{5}{54}\)