maryvale high school is starting a freshman mentoring program. there are eight seniors, twelve juniors, and…

maryvale high school is starting a freshman mentoring program. there are eight seniors, twelve juniors, and four sophomores signed up to mentor. ten mentors will be chosen for the school year. round answers to three decimal places. what are the total number of ways to choose ten mentors from the group of seniors, juniors, and sophomores? what is the probability that the mentors will be five seniors, three juniors, and two sophomores?
Answer
Explanation:
Step1: Calculate total number of students
The total number of students is (8 + 12+4=24).
Step2: Calculate number of ways to choose 10 mentors
We use the combination formula (C(n,r)=\frac{n!}{r!(n - r)!}), where (n = 24) and (r = 10). [C(24,10)=\frac{24!}{10!(24 - 10)!}=\frac{24!}{10!14!}=\frac{24\times23\times22\times21\times20\times19\times18\times17\times16\times15}{10\times9\times8\times7\times6\times5\times4\times3\times2\times1}=1961256]
Step3: Calculate number of ways to choose 5 seniors, 3 juniors and 2 sophomores
Number of ways to choose 5 seniors out of 8: (C(8,5)=\frac{8!}{5!(8 - 5)!}=\frac{8!}{5!3!}=\frac{8\times7\times6}{3\times2\times1}=56) Number of ways to choose 3 juniors out of 12: (C(12,3)=\frac{12!}{3!(12 - 3)!}=\frac{12!}{3!9!}=\frac{12\times11\times10}{3\times2\times1}=220) Number of ways to choose 2 sophomores out of 4: (C(4,2)=\frac{4!}{2!(4 - 2)!}=\frac{4!}{2!2!}=\frac{4\times3}{2\times1}=6) The number of ways to choose 5 - seniors, 3 - juniors and 2 - sophomores is (C(8,5)\times C(12,3)\times C(4,2)=56\times220\times6 = 73920)
Step4: Calculate the probability
The probability (P=\frac{\text{Number of favorable outcomes}}{\text{Total number of outcomes}}) (P=\frac{73920}{1961256}\approx0.038)
Answer:
The total number of ways to choose ten mentors is (1961256). The probability that the mentors will be five seniors, three juniors, and two sophomores is approximately (0.038).