jessica is choosing a 3 letter password from the letters A, B, C, and D. The password cannot have the same letter repeated in it. How many such passwords are possible?
There are 6 passwords for each letter it starts with so a total of 24: ABC, ABD, ACB, ACD, ADB, ADC, BAC, BAD, BCA, BCD, BDA, BDC, CAB, CAD, CBA, CBD, CDA, CDB, DAB, DAC, DBA, DBC, DCA, DCB
