Question

A group of 10 people is choose a chairperson and vice-chairperson. They put all 10 peoples names into a bar. The first name drawn becomes chair. The second name drawn becomes vice-chair. How many possible combinations of chair and Vice-chair are there ?

Answer 1

90

Explanation:

A group of 10 people is choose a chairperson and vice-chairperson. They put all 10 peoples names into a bar. The first name drawn becomes chair. The second name drawn becomes vice-chair. How many possible combinations of chair and Vice-chair are there ?

This is calculated using the Permutation formula

nPr = n!/(n - r)!

Where:

n = 10 people

r = 2 = 2 positions to be filled , Chairman and Vice chairman

Hence:

10P2 = 10!/(10 - 2)!

= 90 ways