I need some more information about pascal's triangle...?

Question

1.fill in the gaps

(a+b)=_+ 8 _+28 _+56 _+70 _+56 _+28 _+8 _+ _

2.What are some of the mysteries about the Pascal triangle.
3.if you were to fold the triangle acrros its altiitude, what are some of the things you might notice?
4.How many binomial coefficients are there in the 10th row pascal's triangle?
5.If the second element in a row is a prime number what can you say about numbers in that row exlluding 1's?

can you anwser any of those questions..please

Answer 1

1. (a+b)^8 = a^8 + 8 a^7 b + 28 a^6 b^2 + 56 a^5 b^3 + 70 a^4 b^4 + 56 a^3 b^5 + 28 a^2 b^6 + 8 a b^7 + b^8

2. See http://en.wikipedia.org/wiki/Pascal's_triangle

3. It is symmetrical

4. 10

5. They are all divisible by that prime number