You are to form a 5 digit number from the digits 1,2,4,6,7,8, and 9, using each at most once.
Total possible = 2520
How many of these (total) are less than 50000?____

Question

You are to form a 5 digit number from the digits 1,2,4,6,7,8, and 9, using each at most once.
Total possible = 2520
How many of these (total) are less than 50000?____

directrix · Answer

3 times 6 times 5 times 4 times 3 = 1080.

-  -  -  -  - 
You have a five-digit number.
The first digit must be 1, 2, or 4.
Use one of them. That leaves 2 digits plus the other 4 (6, 7, 8,9)

So, 3 choices for the first digit plus 6 remaining digits. 

A digit can be used once if that many times.

3 times 6 times 5 times 4 times 3 = 1080.