Question

How many permutations of the letters ABCDEFG contain:
a.) the string BCD?
b.) the string CFGA?
c.) the strings BA and GF?

Answer 1

The strings BCD?
5! >>>>>>>>> [A (BCD) E F G] 

The string CFGA?
4! >>>>>>>>> [B (CFGA) D E]

The strings BA and GF?
5! >>>>> [(BA) C D E (GF)]