How many different 4-letter radio-station call letters can be made if the first letter must be K or W, repeats are allowed, but the call letters cannot end in an O?
A) 16,900
B) 456,976
C) 35,152
D) 33,800

Question

Quizplus · Accepted Answer

For the first letter, there are 2 choices (K or W). For each of the next two letters, there are 26 choices (any letter of the alphabet), and for the last letter, there are 25 choices (any letter except O). So, the total number of combinations is 2 * 26 * 26 * 25 = 33,800.

How Many Different 4-Letter Radio-Station Call Letters Can Be Made