SOLUTION: For an upcoming trail a total of 16 jurors must be selected. Only 12 will be actually deliberate to reach the verdict, but 4 alternates will listen to all the testimony and be pre

Click here to see ALL problems on Probability-and-statistics

Question 465692: For an upcoming trail a total of 16 jurors must be selected. Only 12 will be actually deliberate to reach the verdict, but 4 alternates will listen to all the testimony and be prepared to step in should a regular juror be unable to continue. One of the 12 is the foreperson of the jury.
a) How many different groups can be selected as the regular jury?
b) after the jury has heard all the testimony, 2 jurors must be replaced. what is the probability that the foreperson must be replaced?
c) how many different groups of 2 alternates could be placed on the jury as replacements?

I was thinking of the permutation formula but it did not look right.
Answer by jorel1380(3719) (Show Source):
You can put this solution on YOUR website!
16c12=16x15x14x13x12!/4x3x2x12!=4x5x7x13=1820 different panels possible
--------------
2/12=1/6
--------------
4c2=4x3x2!/2x2!=6