Math Problem Statement
Imagine that you are taking a multiple-choice quiz written in Danish and must guess randomly. Each question has 4 choices and 1 correct answer. Please round all answers to four decimal places.
Calculate the probability that you...
answer the first question correctly.
answer the first 2 questions correctly.
answer the first 3 questions correctly.
answer the first 4 questions correctly.
Submit QuestionQuestion 8
Solution
In this case, for each question, there is one correct answer and three incorrect answers, so the probability of answering any given question correctly is:
And the probability of answering a question incorrectly is:
Now, let's calculate the probabilities for each case:
-
Probability of answering the first question correctly:
- Since the probability of answering one question correctly is , the probability of answering the first question correctly is:
-
Probability of answering the first 2 questions correctly:
- The probability of answering both the first and second questions correctly is the product of the probabilities for each:
-
Probability of answering the first 3 questions correctly:
- Similarly, the probability of answering the first three questions correctly is:
-
Probability of answering the first 4 questions correctly:
- Finally, the probability of answering all four questions correctly is:
Now, rounding all the answers to four decimal places:
- Probability of answering the first question correctly: 0.2500
- Probability of answering the first 2 questions correctly: 0.0625
- Probability of answering the first 3 questions correctly: 0.0156
- Probability of answering the first 4 questions correctly: 0.0039
Let me know if you'd like further clarification or more details!
5 Related Questions:
- What is the probability of answering 5 questions correctly?
- If there are 10 questions, what is the probability of answering all 10 correctly?
- How does the probability change if there are more than 4 answer choices per question?
- What is the probability of answering at least 1 question correctly?
- How would the probability be affected if there were 5 choices per question instead of 4?
Tip:
When calculating the probability of multiple independent events happening in sequence (like answering multiple questions correctly), you can multiply the individual probabilities together.
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Math Problem Analysis
Mathematical Concepts
Probability
Independent Events
Formulas
P(correct answer) = 1/4
P(incorrect answer) = 3/4
Theorems
Multiplication Rule for Independent Events
Suitable Grade Level
Grades 7-9
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