Madeline must have know the material for the test, because if a person
knows the material, that person will always get an A, and Madeline was
one of the students got an A. Is this statement valid modus ponens?

Yes.
If Person Knows Material
     then A
End If

Stated another way

If A 
     Then Person Knows the Material
End If


The test for Madelyn knowing the material is True because of the
second If (actually the first one as well but it is easier to see it
he secons one)

No it is not.  It doesn't follow that all people who get an A
necessarily know the material.

Wikipedia defines "modus ponens" at the link below:

http://en.wikipedia.org/wiki/Modus_ponens

If P, then Q. 
P. 
Therefore, Q.

Let P = Knows the material for the test
    Q = Gets an A

Your statement is:

If P, then Q. 
Q
Therefore, P.

This is not modus ponens.

ansel001 is correct.  This is an example of the fallacy called
"Affirming the Consequent".

Here is a counter-example to show that that this form is not valid logic:
If I am holding an apple, I am holding a piece of fruit.
I am holding a piece of fruit
Therefore, I am holding an apple.

But what if I am holding an orange?

took me a while but I get it.

The Statement does NOT say
Only the people who know material will get an A.

The statements does say, if you know the material you will get an A.

It does not say anything at all about people who don't know the
mterial, hey they might get lucky and get an A as well. It is mute on
people who don't know the material.

The statement does not exclude others who don't know the material from
getting an A.

 Thanks guys, I did flunk this one.

that is correct. If it said "Only people who know the material get an
A", that would be the same as "People get and A if and only if they
know the material". This is a bi-conditional written as p <=> q and it
is equivelent to (p->q) AND (q->p).  With q->p now given, modus ponens
would be in effect.