Kevin is registering at a Web site. He must select a password containing 6 numerals to be able to use the site. How many passwords are allowed if no digit may be used more than once?

Question

anonymous · Answer

how do you figure that out though?

anonymous · Answer

oohh! thank you so much! i understand now!

anonymous · Answer

Let me amend my previous answer.

The first number could be anything 0-9. so 10 choices.
The second number could be anything except the number used for the first. so 9 choices.
And so on.. so total we would get

10*9*8*7*6*5 = 151200