Question

How many strings of length 10 over the alphabet (a, b, c, d] have at least one b somewhere in the string?

a) 310
b) 410 - 310
c) 10.4
d) 10.39

Answer 1

Complete Question

The complete question is shown on the first uploaded image

Answer:

The correct option is B

Step-by-step explanation:

The number of alphabet is n= 4 (a , b , c , d )

Generally the total number of string of length 10 over the 4 alphabets is

`N  =  4^(10)`

Gnerally the number of string of length 10 that does not include b is

`T =  3^(10)`

Generally the number of strings of length 10 over the 4 alphabets that have at least one alphabet b somewhere in the string is

`G  =  N - T`

=>
`G  =  4^(10) -  3^(10)`