MHB How many subjects do I need to prepare for a 90% chance of passing the exam?

  • Thread starter Thread starter declan1
  • Start date Start date
  • Tags Tags
    Exam Probability
AI Thread Summary
To ensure a 90% chance of passing the exam, one would need to prepare a significant number of subjects from the list of 30, with estimates suggesting around 25 subjects for a worst-case scenario. The discussion emphasizes the importance of understanding probability calculations to determine the optimal number of paragraphs to write. Participants express the need to balance preparation with the likelihood of specific subjects appearing in the exam. The conversation highlights the challenge of estimating how many subjects to prepare while considering the workload involved in writing extensive paragraphs. Ultimately, calculating the exact number for a 90% chance remains a complex task that requires further analysis.
declan1
Messages
2
Reaction score
0
I have a scenario where I have a list of 30 subjects that might appear in an online exam.

of the 30, only ten will actually appear in the exam and of those 10, I must select 5 to write a paragraph on.

Given that I have the list of thirty, how many paragraphs would I need to write in advance to ensure that I would have at least 5 of the selected 10?

I am having trouble calculating beyond the first event (each topic having a 1 in 3 chance of being part of the ten).

My instinct says 20, but I think it's likely less than that.

To clarify, my teacher says the learning outcomes are what is important, so having multiple paragraphs pre-prepared is not cheating.
 
Mathematics news on Phys.org
declan said:
I have a scenario where I have a list of 30 subjects that might appear in an online exam.

of the 30, only ten will actually appear in the exam and of those 10, I must select 5 to write a paragraph on.

Given that I have the list of thirty, how many paragraphs would I need to write in advance to ensure that I would have at least 5 of the selected 10?

I am having trouble calculating beyond the first event (each topic having a 1 in 3 chance of being part of the ten).

My instinct says 20, but I think it's likely less than that.

To clarify, my teacher says the learning outcomes are what is important, so having multiple paragraphs pre-prepared is not cheating.

Wellcome on MHB delcan!...

... if You want to guarantee in the 'worst case', then You have to prepare at least 25 subjects... more complex but also much more interesting from the point of view of the calculus of probability would be, for example, calculate how many subjects to prepare for say .9 chance of passing the exam ...

Kind regards

$\chi$ $\sigma$
 
chisigma said:
Wellcome on MHB delcan!...

... if You want to guarantee in the 'worst case', then You have to prepare at least 25 subjects... more complex but also much more interesting from the point of view of the calculus of probability would be, for example, calculate how many subjects to prepare for say .9 chance of passing the exam ...

Kind regards

$\chi$ $\sigma$

Thanks for that, I see what you've done. Simple now really. How about the 90% chance scenario. That would likely be much lower right? I like to live dangerously and have 2 of these exams to prep for. A 'good paragraph' answer being 300 words, that's 15000 words I need to write to guarantee a pass. There must be a high chance ratio that would bring down the writing volume considerably. There are probably a couple from the list of 30 I could also take a punt and say they won't be in the final 10. How would I calculate the 2 scenarios so I can work it out for myself?
 
Suppose ,instead of the usual x,y coordinate system with an I basis vector along the x -axis and a corresponding j basis vector along the y-axis we instead have a different pair of basis vectors ,call them e and f along their respective axes. I have seen that this is an important subject in maths My question is what physical applications does such a model apply to? I am asking here because I have devoted quite a lot of time in the past to understanding convectors and the dual...
Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. In Dirac’s Principles of Quantum Mechanics published in 1930 he introduced a “convenient notation” he referred to as a “delta function” which he treated as a continuum analog to the discrete Kronecker delta. The Kronecker delta is simply the indexed components of the identity operator in matrix algebra Source: https://www.physicsforums.com/insights/what-exactly-is-diracs-delta-function/ by...
Back
Top