permutation and combination
1.Six books with different titles have green covers and three books with different titles have red covers. In how many ways can the nine books be arranged on a shelf if (a) the red books are not to be separated, (b) the green books are not to be separated, (c) books of the same color are to be kept together?
2.If a man has three suits, four shirts, ten ties, six pairs of socks, two hats, and three pairs of shoes, in how many ways can he be dressed?
Could someone help me I desperately need help!!!