1. ## Homework help

Hi! I struggle really with statistics, probability theory and math in general, its really hard for me to understand and figure out by myself the answers of the questions.

Student is taking multiple choice test.
1 question = only 1 correct answer
If student knows the question = 100% correct
If student doesn't know the question = 20% chance of being correct
Student knows 70% of the questions.

1. Probability of answering question correct.
2. Given correct answer, probability that student knows the question.

At Question 1. I tried P(A|B) = P(a)*P(b)/P(b) = 0,7*0,3/0,3 = 0,7 but it doesnt makes sense to me. Haven't even got to second question.

3. ## Re: Homework help

Hi,

Have a look at this video:

Please do not be offended by the title- certainly I found it very helpful previously when I could not answer a question that required Bayes theory.
If you look at 4:00 and try and recreate the diagram of your question I think it will help you visualise the problem.

Good luck!

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