180k views
0 votes
A quiz contains 5 true/false questions and 5 multiple-choice questions, where each multiple-choice question has 4 choices. If you randomly guess on each question, what is the probability of missing at least one question?

A. 97.664%
B. 99.091%
C. 99.997%
D. 98.230%
E. 95.411%

User Seishin
by
7.7k points

1 Answer

5 votes

Final answer:

The probability of missing at least one question on a quiz with 5 true/false and 5 multiple-choice questions, when guessing randomly, is approximately 99.997%, corresponding to answer choice C.

Step-by-step explanation:

To calculate the probability of missing at least one question:

  1. Calculate the probability of getting a question right:
  • True/False question: 1/2 chance of guessing correctly.
  • Multiple-choice question with 4 choices: 1/4 chance of guessing correctly.
Calculate the probability of guessing all questions right:
  • Probability of guessing all true/false questions correctly: (1/2)^5.
  • Probability of guessing all multiple-choice questions correctly: (1/4)^5.
  • Total probability of guessing all questions correctly: (1/2)^5 * (1/4)^5.
Find the complementary probability of not guessing all questions correctly, which gives us the probability of missing at least one question.
  • Complementary probability: 1 - ((1/2)^5 * (1/4)^5).
  • Perform the calculation: 1 - (1/32 * 1/1024).
  • This equals 1 - (1/32768), which simplifies to 32767/32768.
  • Convert to a percentage: (32767/32768) * 100%, roughly 99.997%.

Therefore, the probability of missing at least one question when randomly guessing is approximately 99.997%, which corresponds to answer choice C.

User Alpants
by
8.3k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories