Asked by Anonymous
There are 12 students interested in creating a shoe shining club. There will be a president, a vice-president, 2 shoe shiners, 2 polish selectors, and the rest will work on advertising.
How many ways can these positions be filled?
I did: (12C1)+(12C1)+(12C2)+(12C2)+(12C6) and got 1015 ways as my answer. Is this correct?
How many ways can these positions be filled?
I did: (12C1)+(12C1)+(12C2)+(12C2)+(12C6) and got 1015 ways as my answer. Is this correct?
Answers
Answered by
Reiny
No!
The president can be chosen in C(12,1) ways
the VP can be chosen in C(11,1) ways
the 2 shoe-shiners in C(10,2) ways
the 2 polish selectors in C(8,2) ways, leaving C(6,6) for advertising.
multiply these ....
12x11x45x28x1 = 166320
The president can be chosen in C(12,1) ways
the VP can be chosen in C(11,1) ways
the 2 shoe-shiners in C(10,2) ways
the 2 polish selectors in C(8,2) ways, leaving C(6,6) for advertising.
multiply these ....
12x11x45x28x1 = 166320
Answered by
Anonymous
Thank you Reiny! So just for clarification, you reduce n by how many were chosen previously because those people were already selected and you can't chose them anymore, right?