## Algebra 2 (1st Edition)

a) Using the Fundamental Counting Principle and the example, the number of possible choices is $26\cdot26\cdot26\cdot10\cdot10\cdot10\cdot10=175760000$ b) Using the Fundamental Counting Principle and the example, the number of possible choices is $26\cdot25\cdot24\cdot10\cdot9\cdot8\cdot7=78624000$ (because each previously chosen letter or number cannot be chosen again).