Chapter 11 - Counting Methods and Probability Theory - 11.1 The Fundamental Counting Principle - Exercise Set 11.1 - Page 693: 20

35,152

The number of ways in which a series of successive things can occur is found by multiplying the number of ways in which each thing can occur. --------- Ways of choosing the 1st letter: 2 (either a W or a K) 2nd letter: 26 3rd letter: 26 4th letter: 26 Total: 2$\times$26$\times$26$\times$26=35,152