There are 12 such numbers.
9,000
There are 320 such numbers.
There are 7200 such numbers.
625 if numbers can have leading 0s, 500 otherwise.
2240
500
5*5*4*4 = 400
With a total of 90,000 five digit numbers, we can conclude that there is 45,000 EVEN five digit numbers.
7000 - 999 ie 6001 four digit numbers
900 numbers
There are 12 such numbers.
9,000
There are 320 such numbers.
256 unless you count zero in which case its 625.
90
There are 7200 such numbers.