Math Problem Statement

an elementary school is offering 3 language classes: one in spanish, one in french, and one in german. these classes are open to any of the 116 students in the school. there are 45 in the spanish class, 36 in the french class, and 28 in the german class. there are 17 students that are in both spanish and french, 8 are in both spanish and german, and 7 are in both french and german. in addition there are 4 students taking all three classes. if one student is chosen randomly, what is the probability that he or she is taking at least one language class/ give answer to 3 ddecimal places

Solution

To solve this problem, we will use the principle of inclusion and exclusion.

Step 1: Understanding the data

  • Total number of students: 116
  • Number of students in each language class:
    • Spanish: 45
    • French: 36
    • German: 28
  • Students taking both languages:
    • Spanish and French: 17
    • Spanish and German: 8
    • French and German: 7
  • Students taking all three languages: 4

Step 2: Inclusion-Exclusion Formula

The inclusion-exclusion principle helps us calculate the number of students taking at least one language class. The formula for the union of three sets (students in Spanish, French, or German) is:

SFG=S+F+GSFSGFG+SFG|S \cup F \cup G| = |S| + |F| + |G| - |S \cap F| - |S \cap G| - |F \cap G| + |S \cap F \cap G|

Where:

  • S|S| is the number of students in Spanish (45),
  • F|F| is the number of students in French (36),
  • G|G| is the number of students in German (28),
  • SF|S \cap F| is the number of students in both Spanish and French (17),
  • SG|S \cap G| is the number of students in both Spanish and German (8),
  • FG|F \cap G| is the number of students in both French and German (7),
  • SFG|S \cap F \cap G| is the number of students in all three languages (4).

Step 3: Plug the values into the formula

SFG=45+36+281787+4|S \cup F \cup G| = 45 + 36 + 28 - 17 - 8 - 7 + 4

SFG=81|S \cup F \cup G| = 81

This means 81 students are taking at least one language class.

Step 4: Calculate the probability

The probability that a randomly chosen student is taking at least one language class is the ratio of students taking at least one language to the total number of students in the school.

P(at least one class)=Students in at least one classTotal students=81116P(\text{at least one class}) = \frac{\text{Students in at least one class}}{\text{Total students}} = \frac{81}{116}

P(at least one class)0.698P(\text{at least one class}) \approx 0.698

Final Answer:

The probability that a randomly chosen student is taking at least one language class is approximately 0.698.


Would you like more details on the inclusion-exclusion method or have any further questions?

Here are some related questions:

  1. How would you apply inclusion-exclusion to four sets instead of three?
  2. What is the probability that a student is taking exactly two language classes?
  3. How would you adjust this calculation if some students were not taking any language classes?
  4. What is the probability of a student taking only one language class?
  5. Can you solve for the number of students in each pair of classes (e.g., Spanish and French but not German)?

Tip: The inclusion-exclusion principle helps simplify problems involving overlapping sets, making it much easier to calculate probabilities involving multiple categories!

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Math Problem Analysis

Mathematical Concepts

Probability
Set Theory
Inclusion-Exclusion Principle

Formulas

|S ∪ F ∪ G| = |S| + |F| + |G| - |S ∩ F| - |S ∩ G| - |F ∩ G| + |S ∩ F ∩ G|
P(at least one class) = (Students in at least one class) / (Total students)

Theorems

Inclusion-Exclusion Principle

Suitable Grade Level

Grades 9-12