Asuitcase lock has 3 dials with the digits 0, 1, 9 on each. how many different settings are possible if all three digits have to be different?

Digit 1: 1 number out of 10 total numbers = 1/10
Digit 2: 1 number out of 9 total numbers = 1/9
Digit 3: 1 number out of 8 total numbers = 1/8

Digit 1  AND  Digit 2   AND  Digit 3
  1/10      x      1/9         x        1/8    = 1/720

504 settings. Factorial 

Ibelieve the total for the tip could be $21.90