Case 1 : 4-digit numbers
Given digits -
0,1,2,3,4,5 As the numbers should be greater than 2000 , first digit can be 2, 3, 4 and 5
For remaining digits, we need to arrange 3 digits from the remaining 5 digits, i.e.
5×4×3=60 ways Total number of possible 4-digit numbers
=4×60=240 Case 2: 5-digit numbers
First digit cannot be zero.
Therefore, total number of cases
=5×5×4×3×2=600 Case 3: 6-digit numbers
First digit cannot be zero.
Therefore, total number of cases
=5×5×4×3×2×1=600 Total number of integers possible
=600+600+240=1440 The answer is option A.