Smallest number of combinations...?
There are 1500 students in a high schoole. Each student requires a lock for a personal locker/ The school provides locks.
The locks work so that they have 3 consecutive positions to hit before it opens. Each consecutive position must be different from the one previous (therefore there are 60*59*59 possibilities).
What is the smalleset number of positions that must be in the lock to give each student a unique combination?
I have the answer, i just dont know the method for getitng it:
Answer: 12 positions.