How many permutations does a combination lock have if each combination has 3 numbers, no two numbers of the combination are the same, and the lock dial has 30 notches?
A)12,180
B)73,080
C)48,720
D)24,360
E)none of the above

Question

Quizplus · Accepted Answer

There are 30 choices for the first number, 29 for the second, and 28 for the third. So, the total number of permutations is 30 * 29 * 28 = 24,360.

How Many Permutations Does a Combination Lock Have If Each