Question

Find the number of four digit numbers that do not contain four different digits

Answer 1

heya buddy,
Here is your answer

So, as the question demand a four digit number that don't contain 4 different digits. So, the number may contain:

(i) ALL THE SAME DIGITS
some are written below
1111
2222
3333
4444
etc.

(ii) THREE SAME DIGITS
some are listed below
1112
2223
3334
4445
etc.

(iii) TWO SAME DIGITS
some are listed below
1123
2234
3345
4456
etc.

HOPE THIS HELPS

if you want further help you can ask me. i love to help.

Thank you


-Sneha

Answer 2

Heya!

ATQ, (according to the question)

It has asked for four digit numbers which do not contain our different digits, but it can have-

a)All Same Digits., like- 1111,2222,3333 and so on.

b)Two Same Digits., like- 1122,2233,3311 and so on.

c)Three Same Digits., like- 1113,2223,3332 and so on

Note:- I have taken '1' , '2' and  '3' for making different four digit numbers.But u can take any other number of your choice.

In this pattern, we can have the greatest 4 digit no. as- 9998
and smallest 4 digit no. as- 1000

Note:- these do not contain 4 different digits.

Hope it helps...