+0  
 
+5
611
0
avatar+1072 

1. Find the number of ways to arrange the letters A, B, B, C, C, C. (Both B's are identical, and all three C's are identical.)

 

2. Robin chooses a 4-digit PIN number, so that there are exactly two different digits (like 0777). How many different PIN numbers can Robin choose?

 
 Feb 23, 2020

0 Online Users