Question

Give the digits 0-9, how many 4 digit numbers can be made if digits can be used more than once

Answer 1

9+1  

9+2  

9+3  

9+6  

9+7  

9+8  

and  

8+2  

8+3  

8+6  

8+7  

and  

7+4  

7+6  

7+7  

7+9  

hope it hepls