The numbers 0 through 9 are used in code groups of four to identify an item of clothing. Code 1083 might identify a blue blouse, size medium. The code group 2031 might identify a pair of pants, size 18, and so on. Repetitions of numbers are not permitted, i.e., the same number cannot be used more than once in a total sequence. As examples, 2256, 2562 or 5559 would not be permitted. How many different code groups can be designed?
A) 5,040
B) 620
C) 10,200
D) 120

Question

Quizplus · Accepted Answer

The number of different code groups can be calculated by finding the number of permutations of 4 digits chosen from 10, which is 10P4 = 10! / (10-4)! = 10 × 9 × 8 × 7 = 5,040.

The Numbers 0 Through 9 Are Used in Code Groups