Question

Ishmael's bank does not allow any digit to be repeated in his secret pin number. For

example 7762 would not be allowed, nor would 5075.

Ishmael's bank card is stolen. What is the probability with one guess only that
someone correctly guesses Ishmael's pin number? Leave your answer as a fraction.

Answer 1

`(1)/(4536)`

Explanation:

P=
`(1)/(9*9*8*7)`

=
`(1)/(4536)`

[The calculation of probability]