Hint. You can use the concepts from Set theory and Set operations (Union, Intersection, Set Difference etc.) to solve the counting problems. 1. [4 pts) Counting the number of multiples. How many integers between 100 and 999 (inclusive) (a) are divisible by 42 (b) are divisible by 6? (c) are divisible by both 4 and 6? (d) are divisible by 4 or 6