<p>Ok at the risk of sounding like a complete idiot, I don't get how they got this answer on a practice test. </p>
<p>Here's the question:</p>
<p>Exactly 4 actors try out for the 4 parts in a play. If each actor can perform any one part and no one will perform more than one part, how many different assignments of actors are possible?</p>
<p>They give the Answer 24, I get 16.</p>
<p>Thanks.</p>
<p>Try making a doodle to solve this problem. if you draw 4 circles or something, then you see that in the first circle (the first part for the play) you can only have four possible people in that part. For the 2nd part, you can only have 3 possible people for that part in the play because there's already one person in the first part. For the third and fourth parts of the play you can only have 2 people for the third and 1 person in the 4th part. So you multiply all the possibilities together: 4 x 3 x 2 x 1 = 24 and that's how you get that. If you see a problem like that again just use a factorial; 5!, 4!, etc.</p>
<p>Ohhh...ok that makes sense thanks!</p>
<p>I just did that question! Hee hee</p>