Question

1. Student ID number at a certain University are made up of a letter, followed by six 1-digit

Answer 1

Answer:

650,000,000 student ID numbers are possible if the letters cannot be repeated.

Step-by-step explanation:

The order in which the digits or letters are placed is important, which means that the permutations formula is used to solve this question.

Permutations formula:

The number of possible permutations of x elements from a set of n elements is given by the following formula:

$P_{(n,x)} = \frac{n!}{(n-x)!}$

In this question:

2 letters from a set of 26(permutations, as letters cannot be repeated).

6 digits, each with 10 possible outcomes.

How many student ID numbers are possible if the letters cannot be repeated?

$T = 10^6 \times \frac{26!}{24!} = 650000000$

650,000,000 student ID numbers are possible if the letters cannot be repeated.