answer all questions with explanation

Problem 10. Suppose we have 20 Lego's of the same size of which 10 are red and 10 are blue, but are otherwise identical in appearance. A child randomly stacks the Legos linearly into a 2D-stack of Legos. (a) How many 20-stacks are possible? (b) How many 20-stacks alternate colors? (c) How many 20-stacks have more red Legos in the bottom 10 than blue Legos? We deal 13 cards to each of 4 people from a well-shufed deck. The people are called North, South, East, and West. The following are all separate questions unless stated otherwise. Problem 11. How many deals are possible? Problem 12. How many deals have North receiving all 4 Aces? Problem 13. How many deals have each person receiving exactly one Ace? Problem 14. How many deals have North receiving 2 Aces and South receiving the other 2 Aces