Question

There are 10 board members on the Community Arts Council. In how many ways can a president and treasurer be chosen

Answer 1

45

Explanation:

This is a combination question: how many ways can you pick 2 people from a group of 10?

Using the notation C(10, 2) for the number of combinations of 10 things chosen 2 at a time...

`C(10, 2)=(10!)/(2!(10-2)!)=(10!)/(2!\cdot 8!)=(10\cdot 9)/(2\cdot 1)=45`