Chapter 8.2, Problem 8.27E

(a)

To determine

To calculate how many three character internet domain names are possible that consist of letters only.

Answer to Problem 8.27E

  $17576$ .

Explanation of Solution

Use multiplication counting principle and there are $26$ letters:

  $26\times 26\times 26=17576$

Hence the result.

(b)

To determine

To calculate how many three character internet domain names are possible that consist of numbers or letters.

Answer to Problem 8.27E

  $46656$ .

Explanation of Solution

Use multiplication counting principle and there are $26$ letters and ten numbers:

  $36\times 36\times 36=46656$

Hence the result.