Descriptive statistics question

Question

Question from a homework assignment I'm working on.

There are 40 students in a class.

27 are having trouble in Math, 15 are having trouble in English. 2 are having trouble in both subjects.

Are the two students that are having trouble in both subjects included as part of the population of students having trouble in Math and in English or are they added on top of both populations?

So if 2 students are having trouble in both subjects, could I thus say that there are 29 students having trouble in Math and 17 that are having trouble in English?

Thank you for your assistance

Answer 1

The $2$ people that are having trouble in both subjects are included in the people that's having trouble in Math and English independently.

Let's put it this way:

The total population is the people having trouble in math + people having trouble in english - people having trouble in both.

For example, if you're taking both Calculus class and Linear algebra Class, then there's 1 person taking calculus and 1 person taking linear algebra, but also 1 person taking both, since the population is only 1 - you.

Hope that helps.

Answer 2

I know you got your answer, but as a quick aside - I like to draw diagrams to help me answer questions like this. Venn diagrams are great as you can see the overlap and visualise how the students fit into each class.