Answer:
28 took only the history paper
31 took only the geography paper
6 didn't do any exam.
Explanation:
There is a total of 93 students.
56 took the history paper.
59 took the geography paper
28 students took both of them.
then in the 58 that took the history paper, we are counting the ones that only take the history paper and the 28 that took both papers, then the number of students that only took the history paper is:
56 - 28 = 28 took only the history paper.
We can use the same reasoning for the number of students that only took the geography paper:
59 - 28 = 31 took only the geography paper.
Now let's find the number of students that took neither paper.
First let's calculate the total number of students that took at least one paper, this is:
28 took both papers.
28 took only history
31 took only geography.
Total = 28 + 28 + 31 = 87
And there are 93 students in total, then the number of students that didn't took any paper is equal to the difference between the total number of students, and the number of students that took at least one, this is:
N = 93 - 87 = 6
6 students did not take any paper.