When picking out a username for a particular game the user c

When picking out a username for a particular game the user chooses five letters followed by 2 digits. If letters and digits cannot be repeated, how many usernames are possible?

Select one:

a. 710424000

b. 1188137600

c. 789360000

d. none of the above

Solution

The total number of ways is 26x25x24x23x22x10x9 = 710424000

Letters can be taken from 26 alphabets

digits can be taken from 10 numerals