Question 1210205
<pre>
Case 1: ALL the digits are the same
There are 10 ways all 7 digits can be the same.
That's 10 ways for Case 1.

Case 2:
6 of the digits are the same and 1 is different.

We can choose the digit that occurs 6 times, 10 ways.
We can choose the digit that occur only once, 9 ways.
We can choose the position for the digit that occurs only once, 7 ways.
 
That's (10)(9)(7) = 630 ways for Case 2.

Answer: 10 + 630 = 640 ways.

Edwin</pre>