# NCERT Class 11 Mathematics Solutions: Chapter 16 –Probability Miscellaneous Exercise Part 5

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1. The number lock of a suitcase has wheels, each labelled with ten digits i.e., from . 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?

Answer:

The number lock has wheels, each labelled with ten digits i.e., from .

Number of ways of selecting different digits out of the digits

Now, each combination of different digits can be arranged in Ways.

Number of four digits with no repetitions

There is only one number that can open the suitcase.

The required probability is