Question

A security system has a lock with 5 rings.
Each of these rings is marked with 5 different letters.
Calculate the total number of failed attempts made to open the loc​

Answer 1

GOOD EVENING

QUESTION : A security system has a lock with 5 rings.

Each of these rings is marked with 5 different letters.

Calculate the total number of failed attempts made to open the lock

ANSWER : 1023

EXPLANATION :

Number of options on 1st ring is 4

Number of options on 2nd ring is 4

Number of options on 3rd ring is 4

Number of options on 4th ring is 4

Number of options on 5th ring is 4

∴ Total number of attempts possible

=4×4×4×4×4

=1024

We can open the lock only in one of the total attempts

∴ Number of all possible unsuccessful attempts to open the lock is

=1024−1

=1023