Math Problem Statement

If there are 4 male students and 4 female students, 5 students are chose randomly for a math competition, what are the probability that there are exactly 2 students who are male in the 5 chosen.

Solution

To solve this problem, we will calculate the probability that exactly 2 of the 5 chosen students are male, given that there are 4 male and 4 female students in total.

Steps to Solve:

  1. Total number of students:
    There are 44 male students and 44 female students, so there are 88 students in total.

  2. Total number of ways to choose 5 students from 8:
    This can be calculated using combinations. The number of ways to choose 5 students from 8 is: (85)=8×7×63×2×1=56\binom{8}{5} = \frac{8 \times 7 \times 6}{3 \times 2 \times 1} = 56

  3. Number of ways to choose exactly 2 male students:
    We need to choose 2 male students from the 4 male students, which can be done in: (42)=4×32×1=6\binom{4}{2} = \frac{4 \times 3}{2 \times 1} = 6

  4. Number of ways to choose 3 female students:
    Since we are choosing 2 males, we will need to choose 52=35 - 2 = 3 female students from the 4 females, which can be done in: (43)=41=4\binom{4}{3} = \frac{4}{1} = 4

  5. Number of favorable outcomes:
    The number of ways to choose exactly 2 males and 3 females is the product of the two combinations: 6×4=246 \times 4 = 24

  6. Probability:
    The probability is the ratio of favorable outcomes to the total outcomes: Probability=2456=37\text{Probability} = \frac{24}{56} = \frac{3}{7}

Final Answer:

The probability that exactly 2 of the 5 chosen students are male is 37\frac{3}{7}.

Would you like more details, or do you have any questions?

Here are 5 follow-up questions to expand your understanding:

  1. How would the probability change if there were 5 male students instead of 4?
  2. What is the probability of selecting exactly 3 males and 2 females?
  3. How can you generalize this problem to any number of males and females?
  4. How would you calculate the probability of selecting at least one male?
  5. How does the total number of combinations change if we increase the total number of students?

Tip: Remember that combinations are used when the order of selection does not matter!

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Combinatorics
Probability

Formulas

Combination formula: C(n, k) = n! / (k!(n-k)!)
Probability formula: P(Event) = Favorable Outcomes / Total Outcomes

Theorems

Basic Combinatorics
Probability Theorem

Suitable Grade Level

Grades 9-12