Math Problem Statement

Suppose you ask a friend to randomly choose an integer between 1 and 10, inclusive. What is the probability that the number will be more than 5 or odd?

Solution

Let's solve this problem step-by-step.

Problem Summary

We're asked to find the probability that a randomly chosen integer between 1 and 10 (inclusive) will be either:

  1. Greater than 5, or
  2. An odd number.

Let's denote:

  • Event AA as the event that the number is greater than 5.
  • Event BB as the event that the number is odd.

Step 1: Identify Numbers for Each Event

  1. Event AA: Numbers greater than 5

    • The integers greater than 5 within the range 1 to 10 are: 6,7,8,9,6, 7, 8, 9, and 1010.
    • So, there are 5 numbers in this set.
  2. Event BB: Odd numbers

    • The odd integers within the range 1 to 10 are: 1,3,5,7,1, 3, 5, 7, and 99.
    • So, there are 5 numbers in this set as well.

Step 2: Find the Overlap (Intersection) of Events AA and BB

  • The numbers that are both greater than 5 and odd are: 77 and 99.
  • There are 2 numbers in this intersection set.

Step 3: Calculate the Probability Using the Addition Rule

The probability of either event AA or BB occurring is given by: P(AB)=P(A)+P(B)P(AB)P(A \cup B) = P(A) + P(B) - P(A \cap B) where:

  • P(A)=510P(A) = \frac{5}{10},
  • P(B)=510P(B) = \frac{5}{10},
  • P(AB)=210P(A \cap B) = \frac{2}{10}.

So, P(AB)=510+510210=810=45.P(A \cup B) = \frac{5}{10} + \frac{5}{10} - \frac{2}{10} = \frac{8}{10} = \frac{4}{5}.

Answer

The correct probability that the number chosen will be more than 5 or odd is: 45\frac{4}{5}

Would you like further details, or do you have questions?


Related Questions

  1. What is the probability that a number chosen is less than 5 or even?
  2. If the range is extended from 1 to 20, how would the probability change?
  3. How do we calculate probabilities when dealing with more complex overlaps?
  4. What is the probability of selecting a number that is exactly divisible by 3?
  5. How would the answer change if only odd numbers could be chosen?

Tip

When calculating probabilities involving "or" statements, remember to account for any overlap to avoid double-counting.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Probability
Set Theory
Addition Rule for Probability

Formulas

P(A ∪ B) = P(A) + P(B) - P(A ∩ B)

Theorems

Addition Rule of Probability

Suitable Grade Level

Grades 7-10