A certain four-cylinder combination lock has 50 numbers on it.
It is a four cylinder combination lock
Each cylinder has 50 numbers
So we have to choose 4 numbers for 4 cylinders
_____ , ______ , ______, _____
you turn to a number on the first cylinder
We have 50 numbers so we have 50 combinations
__50___ , ______ , ______, _____
Repetitions are allowed so we do the same for remaining three
50 , 50 , 50 , 50
50 * 50 * 50* 50 = 6250000
There are 6250000 different lock combinations .