No. Of Digit

its pretty simple......since the max limit is 10^5 this logic will work...
_ _ _ _ _
we have to fill these 5 blanks such that one of them shud atleast contain 5
so fixing 1ne as 5 each of the oder blanks can have 10 possibilities..
so 10^4 possibilities
now 5 can be placed in any of the five blanks so total ways result to 5 x 10^4...
now you may ask me wat abt de 1,2,3 or 4 digit no.s
dont worry it is included in this calculation(if it is a single digit den de first four digits of this no will be 0 and so on)....

i think it should be simply 50000