You can answer any 10 questions from a total of 12 questions on an exam. In how many different ways can you select the questions?

Feb 9, 2018

$66$ different ways

Explanation:

Because order doesn't matter in this problem, we use the combination formula.

We are picking $10$ from a set of $12$, so $n = 12$ and $r = 10$.

color(white)("two")_nC_r = (n!)/((n - r)!r!) = (12!)/((12 - 10)!10!) = 66

Hence, there are $66$ different ways you can select the questions.

Hopefully this helps!