PERMUTATION/COMBINATION:

1. How many ways can you place 12 t-shirts into 4 different wardrobes: (a) if the t-shirts are identical? (b) if no two t-shirts are the same, and the position of the t-shirts on the wardrobes matter?

2. How many integers between 1 and 300 (inclusive) that are (a) Divisible by 3 or 5 or 7? (b) Divisible by 3 and 5, but not 7? (c) Divisible by 5 but not 3 nor 7? Show your calculation.