How many 5-digit personal identification numbers are possible if the number cannot contain a zero?

59049 digits

Step-by-step explanation:

Given

Digits = 0 to 9

Required

Determine number of 5 digit pins that must not contain 0

There are 10 digits.

Since the pin must not contain 0, there are 9 digits left to select from.

The question didn't state that a digit can not be repeated, so I'll assume that repetition of digit is allowed.

The 1st digit of the 5 could be any of the 9 digits

The 2nd could be any of the 9 digits

The 3rd could be any of the 9 digits

The 4th could be any of the 9 digits

The 5th could be any of the 9 digits

Hence, number of selection is calculated as this:

Selection = 9 * 9 * 9 * 9 * 9

Selection = 59049

If you graph all of the lines that are listed, the only line that will reflect ABCD onto itself is x + y = 4.

Step-by-step explanation:

hope this helps you :)