Question

You have to answer 2 essay questions for an exam. There are 6 essays to choose from. How many different groups of 2 essays could you possibly choose?

Answer 1

The answer is 3 groups of 2 essays

Answer 2

You could possibly choose 15 different groups of 2 essays.

Explanation:

The order in which the questions are chosen is not important. So the combinations formula is used to solve this question.

Combinations formula:

`C_(n,x)` is the number of different combinations of x objects from a set of n elements, given by the following formula.

`C_(n,x) = (n!)/(x!(n-x)!)`

In this problem, we have that:

2 essays from a set of 6. So

`C_(6,2) = (6!)/(2!(6-2)!) = 15`

You could possibly choose 15 different groups of 2 essays.