Question

A locker combination system uses three digits from 0 to 9. How many different three-digit combinations with no digit repeated are possible?

Answer 1

Explanation:

Given that a locker combination system uses three digits from 0 to 9.

Repitition is not allowed.

Three digits can start with 0 also.

Here since order matters, permutation should be used.

Hence 3 digits for lock without repitition from 10 digits can be done in 10P3 ways

=10*9*8

=720

There are 720 different combinations