In a class 20 pupils like science, 13 pupils like history,8 pupils like both subjects and 9 pupilz do no not like either subject..use a Venn diagram to find how many pupils were in the class.....?? Help me

so, did you draw and label the Venn diagram yet? It should be clear that the number of students is

20+13-8+9

Make a rectangle and draw two overlapping circles.

in the intersection put the 8

subtract 8 from the 20 and put 12 in one of the pieces of the circle.

Then subtract 8 from 13 and place 5 in the other open part of the circle

Put the 9 in the rectangle, but not in the circle.

add 9, 8, 12, 5 to get the number of students.

Always remember when there is an overlap, you have to subtract that overlap from the other numbers.

To solve this problem using a Venn diagram, we should start by drawing two circles to represent the subjects: science and history. The overlapping area in the center of the circles will represent the number of students who like both subjects.

Given the information:
- 20 pupils like science
- 13 pupils like history
- 8 pupils like both subjects
- 9 pupils do not like either subject

Let's fill in the information on the Venn diagram step by step:

1. Start by labeling the circles as "science" and "history".
2. Write "20" inside the circle representing science, as there are 20 pupils who like science.
3. Write "13" inside the circle representing history, as there are 13 pupils who like history.
4. In the overlapping area of the circles, write "8", as there are 8 pupils who like both subjects.
5. Finally, outside the circles, write "9", as there are 9 pupils who do not like either subject.

Now, let's calculate the total number of pupils in the class:
- Add the number of pupils who like science (20) to the number of pupils who like history (13).
- Then subtract the number of pupils who like both subjects (8) since they were counted in both subject groups.
- Finally, add the number of pupils who do not like either subject (9) to get the total number of pupils in the class.

Total number of pupils in the class = 20 + 13 - 8 + 9 = 34

So, there are 34 pupils in the class.