Answer:
90 different ways
Explanation:
We have a total of 10 members, and we want to find how many groups of 2 members we can have, where the order of each member in the group of 2 is important, so we have a permutation problem.
To solve this problem, we need to calculate a permutation of 10 choose 2.
The formula for a permutation of n choose p is:
![P(n, p) = n! / (n - p)!](https://img.qammunity.org/2021/formulas/mathematics/college/3dgjqa1qp8i94g326nqq0hw2s8hqj9p78k.png)
So we have:
![P(10, 2) = 10! / (10 - 2)!](https://img.qammunity.org/2021/formulas/mathematics/college/ynz6sfmrvjdp8fj69ldidq86hpk7qbixfk.png)
![P(10, 2) = 10! / 8!](https://img.qammunity.org/2021/formulas/mathematics/college/q7mjfs7w70504be4s3uifij4s4z90mvrtu.png)
![P(10, 2) = 10*9 = 90](https://img.qammunity.org/2021/formulas/mathematics/college/ed3p2aulmicba4czygciv4ajtel8r2iw2c.png)
So there are 90 different ways of choosing a president and a vice-president.