Checkpoint 3.2.4. WebWork - Counting without Counting.

Find how many positive integers with exactly four decimal digits, that is, positive integers between 1000 and 9999 inclusive, have the following properties:
(a) are divisible by 5 and by 7.
(b) have distinct digits.
(c) are divisible by 5 or by 7 (inclusive or).
(d) are divisible by 5.
Answer 1.Answer 2.Answer 3.Answer 4.
in-context