Answer:
I will answer in English.
This can be translated to:
In a school, 1256 girls and 1593 boys study in three periods. how many students study at that school?
This means that we have a total of:
(1256 + 1593) students = 2849 students, divided in 3 periods.
So the total number of students in that school is 2849
And the number of students per period is:
2849/3 = 949.7
Because we can only have whole numbers here, we can say that in each period there are around 950 students.
