Hint. It is usually a good idea with counting problems to establish a step-by-step procedure for constructing the situation you want, then find the number of ways to do each step, then combine your answers to get the final result. For your first problem:
(1) Choose the digit which is going to occur four times. . . . . $10$ ways
(2) Choose the four locations in which this digit will occur. . . . . $C(7,4)$ ways
(3) Choose three digits from the remaining six, with repetition disallowed and order important
. . . . . ??? ways.
Final answer, ??? ways. Note that this assumes a number can start with $0$ - if not, you will have to consider various cases.
See if you can do it from here. Good luck!