How many students take this exam (percentages problem)?

[Guest]

Hi guys! I have a real life math problem and I would love your help and advice in understanding how it works.

I'm making a course for people who want to take an English exam, and I'd like to know about the size of the market. But the company who make the exam don't release the number of students taking the exam. So I need to estimate! Luckily I do have a list of data, organised by country, which shows the percentage of students in each country who got each grade (A, B, C, D and Fail).

I would like to know the minimum possible number of students in each country, given those percentages, who took the exam in 2016.

You can find the orginal list http://gradestatistics.cambridgeenglish.org/2016/fce.html.

And this is an example of a line of data from the table:

Albania Grade A: 13.2% Grade B: 19.4% Grade C: 43.2% Grade D: 18.9% Fail: 5.3%

Given these percentages, how can I calculate an estimate for the lowest possible number of students who took the exam in Albania?

I would love to know the method for finding this out so I can a) learn some maths and b) do the calculations myself.

Thanks so much for your help!

Sam

[Guest]

You are creating an interesting project for students from all over the world to study subjects, sounds cool) Earlier, I once wanted to make a math course for high school students so that they could pass the exam brilliantly. I studied research from PhDs in various subjects. After all, you need to create a curriculum that will be interesting and help students to study. I haven't been able to resolve this issue so far. And therefore has not yet published the final version of his program.

[Maxut]

I wonder if you managed to calculate the percentage of those who passed the exam successfully?) My classmate and I wanted to solve a similar problem for half a day, but we could not.