If a radio station call letters must begin with either K or W and must include either two or three additional letters, how many different possibilities are there?

There are a total of 26 letters that can be made to follow. There are 4 independent events here, namely:

First: Starts with K and followed by two additional letters = 1 * 26 * 26 = 676

Second: Starts with K and followed by three additional letters = 1 * 26 * 26 * 26 = 17,576

Third: Starts with W and followed by two additional letters = 1 * 26 * 26 = 676

Fourth: Starts with W and followed by three additional letters = 1 * 26 * 26 * 26 = 17,576

The total possibilities that can be made from here is:

Total possibilities = 676 + 17,576 + 676 + 17,576

Total possibilities = 36,504