| th | h | t | o |
| 3 | 5 | 5 | 5 |
One's place can be occupied by any of the 5 numbers, tens place by any of the 5 numbers and hundreds place in 5 ways since repetition is allowed. But thousands place can be occupied by 2,3,1, only since the required number should be greater than 1000 and less than 5000.Hence total number of arrangement=3x5x5x5=375



which is purely imaginary number.
Also when y=0, the number will become zero


