question 5,8 and 9 are answered.please help me with the rest. I will appreciate.

2. How many permutations of letters A,B,C,D,E contain substring AB or CD or both? 3. In how many ways is it possible to place 12 equal balls into 4 boxes if in each box are after each placement at least two balls. Give the reason of your answer 4. Let X-fa,b,c/ and Y [1,2/. Find the number of all functions from Xto Ythat are onto. Give the reason of your answer. 5. For given expression (x+1)H y + z)s a) Find the number of elements of expansion b) Find the coefficient of element x'y2z 6. Let R be a relation on the set X-f1,2,3,4,5,6? given by the following description: R= {[1 ,4], [2, 3], [3,2], [4,6 ].[5,2 ] }. Find the smallest relation S on X such that S contains relation R and is transitive (relation S is called transitive closure of R) 7. Let R be relation on set A-fa,b,c,d,e? given by pairs [a,bj, [b,b], [b,c], [d,e], [e,e] Find the smallest equivalency relation R' such that RCR 8. Find all maximal and minimal elements in the partially ordered set S- (fI, 2, 3, 4 6, 8, 9,, Draw Hasse diagram of this set. The relation, l'is defined as alb if and only if b-ka for some keZ 9. Find the number of the terms in the expansion of the expression ( + b + c + d)8. 10 a) How many relations are there on the set \a, b, c? b) How many relations are there on the set {a, b, c} that contain the pair (a, a)? c) How many relations of equivalence are there on the set {a, b, c} that contain the pair (a, b)