A die is rolled 4 times. The probability of getting a larger number than the previous number each time is `17//216` b. `5//432` c. `15//432` d. none of these

Explanation

Total number of cases = `6^(3) = 216`.
If a larger number appears than the previous number each time, all the three number are distinct.
Three numbers can be selected from six numbers in `.^(6)C_(3) = 20` ways and there is only one way in which three selected numbers can appear.
Hence, required probability = `(20)/(216) = (5)/(54)`