Question

How many strings of six lowercase letters from the English alphabet contain

a) the letter a?

b) the letters a and b?

c) the letters a and b in consecutive positions with a preceding b. with all the letters distinct?

d) the letters a and b, where a is somewhere to the left of b in the string, with all the letters distinct?

Answer 1

the letters a and b becasue those are the first two letters