Question

A student number system for a county requires that the student number be 4 characters. The first 3 characters are any single-digit number and cannot repeat, and the last character must be a letter. How many unique student numbers are possible?

a) 260,000
b) 18,720
c) 131,040
d) 315,160

Answer 1

The total number of unique student numbers possible is 13,104.

Step-by-step explanation:

To find the number of unique student numbers that are possible, we need to consider the restrictions given.

The first three characters are any single-digit numbers that cannot repeat, giving us 9 choices for the first character, 8 choices for the second character, and 7 choices for the third character. The last character must be a letter, giving us 26 choices.

To calculate the total number of unique student numbers, we multiply these choices together: 9 x 8 x 7 x 26 = 13,104.