Solution:
Numbers greater than 1000 and less than or equal to 4000 will be of 4 digits and will have either 1 (except 1000) or 2 or 3 in the 1st place with 0 in each of remaining places. After fixing 1st place, the 2ndplace can be filled by any of the 5 digits. Similarly the 3rd place can be filled up in 5 ways and 4th place can be filled up in 5 ways. Thus, there will be 5 x 5 x 5 125 ways in which 1 will be in first place but this also
includes 1000. Hence, there will be I 24 numbers having 1 in the first place. Similarly, 125 for each 2 or 3. one number
will be there in which 4 will be in the first place, i.e., 4000. Hence, the required number of ways is 124 + 125 + 125 + 1375.
