A Poker club has 10 members. A president and a vice-president are to be selected. In how many ways can this be done if everyone is eligible?

90 different ways

Step-by-step 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:

So we have:

So there are 90 different ways of choosing a president and a vice-president.

1/4 because there is 4 grades.

y = 2x

step-by-step explanation:

if you divide each number in the sequence, you'll see that they all have a multiple factor of 2. each number in the series, and any other numbers which may continue, will be multiplied by 2. therefore, y is the next number in the sequence, and x is the current one, so, our formula will be y = 2x.