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Math Homework help

Basically a review sheet but i can't seem to remember how to do these problems.

1) A classmate makes a conjecture that if two angles are supplementary, then one of the angles is acute and the other is obtuse.
*Give a counterexample that shows that the classmate's conjecture is not correct.

2)In a game involving a spinner. If the arrow lands on a shaded region(2/6 shaded) then the player wins 4 points. If the arrow lands on an un shaded region(4/6 unshaded), the player loses 2 points. Is this a fair game?
*Explain your answer using the average expected payoff for one spin.
*What does the negative expected value mean What does the positive expected value mean?

3) Keisha has started a collection of plates with painted scenes of cities she has visited. So far, she has collected 5 plates, with scenes from New York, Asbury Park, Philadelphia, Boston, and Chicago. Right now, she has 1 shelf that can hold 3 plates in a row. hGw many permutations are there for arranging 3 of the 5 plates in a row on the display shelf?
* How many combinations are there for arranging 3 of the 5 plates on the display shelf?
*How does the # of permutations compare with the # of combinations?
*Explain why the # of permutations is different than the number of combinations.

These are the only questions i can't seem to remember how to solve out of the 30 she gave us. All help appreciated.