Answer to Question #146444 in Combinatorics | Number Theory for Josh

Question

How many 4-letter words can be formed from the letters A, B, C, D, E, F if the first letter must not be a vowel and repetition of letters is not allowed?
a.240
b.300
c.360
d.200

Answer 1

The first letter must be B, C, D or F.

The second letter can be 1 of 5 left, third - one of 4 left and fourth - one of

3 left.

So, N=5*4*3*4=240.

Ans. a. 240.