A)How many different five-digit numbers can be formed from the set of seven numbers if repetition is not allowed?

B)Repetition is allowed and the third digit must be different from the second digit?

Determine the number of ways of arranging the letters of the word "MUSCLE"

C)If there are no restrictions?

D)The third and fourth letter must be both consonants?

E)How many possible Canadian postal codes are there?(recalled that our postal codes have the following form: let her number letter, number lettter ,number) ?