Find how many positive integers with exactly four decimal digits, that is, positive integers between 1000 and 9999 inclusive, have the following properties:
(a) have distinct digits.

(b) are divisible by 5 or by 7 (inclusive or).

(c) are divisible by 5.

(d) are divisible by 5 but not by 7.

You can earn partial credit on this problem.