Question

How many three-letter combinations can you make with the letters a, b, c, and d, if you may use a letter more than once in any combination

Answer 1

Answer: With four letters, a, b, c, and d, there are 4 choices for each position in a three-letter combination, and each position is independent of the others. Therefore, there are 4 * 4 * 4 = 64 possible three-letter combinations using the letters a, b, c, and d.

Explanation: