Question

Please help! Correct answer only! This assignment is due today.

A student has to choose an elective class for the last semester of high school. His counselor suggested 8 electives, 5 of which were dance classes.

If the student randomly chose to read about 4 of the electives, what is the probability that all of them are dance classes?

Write your answer as a decimal rounded to four decimal places.

Answer 1

Probability ≈ 0.0714

Explanation:

Consider permutation and combination;

`Total Combinations - 8C4,\\8C4 = 8! / 4! * ( 8 - 4 )!,\\8 * 7 * 6 * 5 / 4!,\\\\Total Combinations = 70,\\\\Combinations of Dance Classes - 5C4,\\5C4 = 5! / 4! * ( 5 - 4 )!,\\5 * 4 * 3 * 2 * 1 / 4 * 3 * 2 * 1,\\\\Dance Classes = 5,\\\\Probability - 5 / 70 = 0.0714,\\Conclusion; Probability = ( About ) 0.0714`