00:01
Okay, we have here then five math people and seven physics people to choose from.
00:06
And my committee has two math and three physics.
00:11
So, a number of ways it can be done if we can include anybody.
00:16
So i've got to have two math people.
00:20
I have five to choose from.
00:21
So it's five choose two.
00:24
Five c two.
00:26
I have seven of these to choose from, physics.
00:29
I want three of them so seven c three this i work out on a calculator or manually if you like five factorial over three factorial two factorial is five c2 sorry that will be three factorial here seven c three seven factorial four factorial three that's the ncr formula that you will find a little formula sheets or easier just use the ti 84 class calculator and just type in 5c2 5c2 i can see here will be 10 and i'll just do 7c3 so press the math button go across to prob number 3 on the list is ncr 7c3 is 35 the answer here is 350 possible ways to form the committee.
01:47
Now in part b, we must have one particular person from physics on the committee.
01:52
That person is going to be fixed.
01:55
So no choice there.
01:57
So math is the same...