ExplanationThis is a permutation problem, so lay out your slots to fill and then multiply.

For choice (A) you have 1 slot for a letter and two slots for digits. There are 26 choices for your letter and 10 choices for your first digit. Because you can’t repeat digits, there are 9 choices for your second digit. Thus, the number of different codes that can be made is 26 × 10 × 9 = 2,340.Eliminate choice (A).

For correct choice (B), you have two spots for letters and two for digits, so you have 26 × 26 (letters can repeat) × 10 × 9 = 60,840.

Choice (C) is incorrect because the number of different codes consisting of one letter and one digit is 26 × 10 = 260.

The only correct answer is choice (B).
_________________

Sandy

If you found this post useful, please let me know by pressing the Kudos Button

Try our free Online GRE Test