Question 743481
There are 5 choices for the first slot


4 choices for the second (you can't reuse one digit, so you have 5-1 = 4 left)


and 3 choices for the third slot


So there are 5*4*3 = <font color="red">60</font> different 3 digit numbers to form (using 1, 2, 3, 4, 5 only)