Math Problem Statement

Question 28: Select the most appropriate answer. For two events A and B, P(A) = 0.8, P(B) = 0.2, and P(A and B) = 0.16. It follows that A and B are: A) disjoint but not independent. B) independent but not disjoint. C) complementary. D) neither disjoint nor independent. E) both disjoint and independent. Question 29: Solve the problem. A number between 1 and 10, inclusive, is randomly chosen. Events A and B are defined as follows: A: {The number is even}. B: {The number is less than 7}. Identify the sample points in the event A ∩ B. A) {1, 2, 3, 4, 5, 6, 7, 8, 10} B) {1, 2, 3, 4, 5, 6, 8, 10} C) {2, 4, 6} D) {1, 2, 3, 4, 5, 6, 7, 9}

Solution

Let's go through each of the questions in the image.

Question 28:

We are given:

  • P(A)=0.8P(A) = 0.8
  • P(B)=0.2P(B) = 0.2
  • P(AB)=0.16P(A \cap B) = 0.16

We need to determine the relationship between events AA and BB.

  1. Check if AA and BB are independent: Two events AA and BB are independent if: P(AB)=P(A)×P(B)P(A \cap B) = P(A) \times P(B) Let's check: P(A)×P(B)=0.8×0.2=0.16P(A) \times P(B) = 0.8 \times 0.2 = 0.16 Since P(AB)=0.16P(A \cap B) = 0.16, AA and BB are independent.

  2. Check if AA and BB are disjoint: Two events are disjoint if P(AB)=0P(A \cap B) = 0. Since P(AB)=0.160P(A \cap B) = 0.16 \neq 0, the events are not disjoint.

So, the correct answer is:

  • B) Independent but not disjoint.

Question 29:

We are asked to identify the sample points in the event ABA \cap B.

  • AA is the event where the number is even: A={2,4,6,8,10}A = \{2, 4, 6, 8, 10\}.
  • BB is the event where the number is less than 7: B={1,2,3,4,5,6}B = \{1, 2, 3, 4, 5, 6\}.

The event ABA \cap B represents the numbers that are in both AA and BB. So, we need to find the intersection of the two sets: AB={2,4,6}A \cap B = \{2, 4, 6\}

Therefore, the correct answer is:

  • C) {2, 4, 6}.

Would you like further details or explanations on any part of these solutions? Here are 5 related questions that you could explore:

  1. How do you test if two events are disjoint using probabilities?
  2. What is the difference between disjoint and independent events?
  3. How do you calculate the intersection of two events with known probabilities?
  4. If P(A)=0.8P(A) = 0.8, what is the probability of the complement of event AA?
  5. How does the concept of mutually exclusive events apply to real-life situations?

Tip: Always double-check whether two events are independent by comparing P(AB)P(A \cap B) to P(A)×P(B)P(A) \times P(B).

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Math Problem Analysis

Mathematical Concepts

Probability
Set Theory
Intersection of Events

Formulas

For independent events: P(A ∩ B) = P(A) × P(B)
Disjoint events: P(A ∩ B) = 0

Theorems

Independence of Events: Two events A and B are independent if P(A ∩ B) = P(A) × P(B).
Disjoint Events: Two events are disjoint if P(A ∩ B) = 0.

Suitable Grade Level

Grade 11-12 (Probability and Set Theory)