need help with some discrete math problems

[jhon13]

Hello ,there are 4 problems on the review that i don't know how to do , please help me.

1) A 64 x 64 grid is filled with 2 x 2 matrices. The four entries in each matrix are chosen without replacement from the set { a,b,c,d,e,f}. What is the least number of identical matrices guaranteed to appear in the grid? Justify your answer.

2) Find the number of ways each situation below can occur:
a) a ticket office has 5 reserved seat tickets and 8 general admission tickets to sell to 15 customers.

b) Billy gets to pick 9 candy bars from the candy rack, which has Snickers, mars, Payday, Mounds, and Crunch.

3)Use inclusion-Exclusion to find the nuber of 4-digit numbers with at least one 8(hint: let A_i = the set of all 4-digit numbers with an 8 position i).

4) Let T be the divisibility relation ( that is , a T b means a divides b). If this relation is defined on the set { 2,5,8,10,16,20,25,40,50,80}, anwser the following:
a) Draw the Hasse diagram for this poset.
b) List the maximal elements of T
c) write out a total ordering which contains this partial ordering but is different from the standard ordering.

I did 4a , but i'm not sure about part b and c.

 

[lookagain]

Hello ,there are 4 problems on the review that i don't know how to do , please help me.

4) Let T be the divisibility relation ( that is , a T b means a divides b).
If this relation is defined on the set { 2,5,8,10,16,20,25,40,50,80}, anwser the following:
a) Draw the Hasse diagram for this poset.
b) List the maximal elements of T
c) write out a total ordering which contains this partial ordering but is different from the standard ordering.

I did 4a , but i'm not sure about part b and c.

jhon13,

post different problems in different threads and don't post problems
without showing your attempts/work for those.

Also, you claim to have done 4a, but you showed
no evidence for that.