Redundant Digits

~~Removed~~

30 Mar 21

~~Removed~~

30 Mar 21

How many integers between 1000 and 9999 inclusive have at least one repeated digit?

on the payroll

31 Mar 21

@joe-shmo said
How many integers between 1000 and 9999 inclusive have at least one repeated digit?

Do numbers like 1030 count? [two zeros, but not back-to-back]

~~Removed~~

31 Mar 21

@bigdoggproblem said
Do numbers like 1030 count? [two zeros, but not back-to-back]

Yeah, the 0 is considered a repeated digit in your example.

tinyurl.com/bdeub4va

31 Mar 21

2 edits

@joe-shmo said
How many integers between 1000 and 9999 inclusive have at least one repeated digit?

Easiest approach to this is to find how many DON'T have a repeat.

on the payroll

31 Mar 21

@AThousandYoung

The method is right, but there are two errors in the arithmetic.

1)

2)

Solution:

~~Removed~~

31 Mar 21