A combination lock on a suitcase has 3 wheels, each labelled with nine digits from 1 to 9. If an opening combination is a particular sequence of three digits with no repeats, what is the probability of a person guessing the right combination ?

The number lock of a suitcase has 4 wheels, each labelled with ten digits i.e., from 0 to 9. The lock opens with a sequence of four digits with no repeats. What is the probability of a person getting the right sequence to open the suitcase?

The number lock of a suitcase has 4 wheels, each labelled with ten digits i.e. from 0 to 9. The lock opens with a sequence of four digits with no repeats. What is the probability of a person getting the right sequence to open the suitcase.

A number lock on a suitcase has three wheels each labelled with ten digits 0 to 9. If opening of the lock is a particular sequence of three digits with no repeats, how many such sequences will be possible? Also, find the number of unsuccessful attempts to open the lock.

A three digit number is chosen, what is the probability of having digits in increasing order from left to right .

A bag consists of 10 balls each marked with one of the digits 0 to 9. If four balls are drawn successively with replacement from the bag, what is the probability that none is marked with the digit 0?

Lock of a safe consists of five discs each of which features the digits 0, 1, 2, ….., 9. The safe can be opened by dialing a special combination of the digits. If the work day lasts 13 hours and to dial one combination of digits takes 5 seconds, then number of days sufficient enough to open the safe, are

An automobile license plate number issued by a certain state has 6 character positions. Each of the first 3 positions contains a single digit from 0 through 9. Each of the last 3 positions contains 1 of the 26 letters of the alphabet. Digits and letters of the alphabet can such license plate number can be made?

A bag contains some white and some black balls, all combinations being equally likely. The total number of balls in the bag is 12. Four balls are drawn at random from the bag at random without replacement and all of them are found to be Black, then the probability that the bag contains 1 white and 9 black balls is

Two Polaroids, P_(1)andP_(2) are set-up so that their pass-axis are crossed with respect to each other. A third Polaroids, P_(3) is now introduced between these two so that its pass-axis makes and angle theta with the pass-axis of P_(1) . A beam of unpolarised light, of intensity I, is incident on P_(1) . If the intensity of light, that gets transmitted through this combination of three Polaroids is I' find the ratio ((I')/(I)) when theta equals. (i) 30^(@)" "(ii)45^(@)

Numbers of three digits with repetition using digits {1, 2, 3, …..9} are formed. The probability that a selected number is divisible by 5 is