SOLUTION: From a group of 10 joggers and 15 nonjoggers, a university researcher will choose 5 people to participate in a study of heart disease. a. In how many ways can this be done if it

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Question 1175414: From a group of 10 joggers and 15 nonjoggers, a university researcher will choose 5 people to participate in a study of heart disease.
a. In how many ways can this be done if it does not matter how many of those chosen are joggers and how many are nonjoggers?
b. In how many ways can this be done if exactly 3 joggers must be chosen?
c. Find the probability that exactly 3 of the 5 people randomly selected from the group are joggers.

Answer by VFBundy(438) About Me  (Show Source):
You can put this solution on YOUR website!
a. In how many ways can this be done if it does not matter how many of those chosen are joggers and how many are nonjoggers?

25C5 = 25%21%2F%285%21%2A20%21%29 = 53130

b. In how many ways can this be done if exactly 3 joggers must be chosen?

10C3 * 15C2 = %2810%21%2F%283%21%2A7%21%29%29+%2A+%2815%21%2F%282%21%2A13%21%29%29 = 120 * 105 = 12600

c. Find the probability that exactly 3 of the 5 people randomly selected from the group are joggers.

%2810C3+%2A+15C2%29%2F%2825C5%29 = = %28120+%2A+105%29%2F53130 = 12600%2F53130 = 60%2F253 = 0.2372