Bekah has exactly three brass house number digits: 2, 3 and 5. How many distinct numbers can she form using one or more of the digits?
Using one digit: 2, 3, 5
Using 2 digits: 23, 25, 32, 35, 52, 53
Using 3 digits: 235, 253, 325, 352, 523, 532
In total, she can form 15 numbers.
We can calculate it by considering permutations, which is P31+P32+P33=3+6+6=15
thanks
+315 
