Question

find the probability of guessing the top two winners (in any order) from a group of 18 finalists in a spelling bee.

the probability that someone correctly predicts the top two winners from a group of 18 finalists is
(type an integer or a fraction.)

Explanation:

Calculate total possible outcomes

Using the Combinations knowledge point

$$ \binom{18}{2} = \frac{18 \times 17}{2 \times 1} = 153 $$

Calculate probability of correct guess

Using the Probability knowledge point

$$ P = \frac{1}{153} $$

Answer:

The probability that someone correctly predicts the top two winners from a group of 18 finalists is <blank>\(\frac{1}{153}\)</blank>