Question

In a class of 36 students, 19 read Biology, 16 read Chemistry and 5 were not allowed to read both subjects. Illustrate the information on a venn diagram. Find how many students read: 1. 11. both Biology and Chemistry; only Chemistry.​

Answer 1

Explanation:

let u represent the universal set

B represent biology

C represent chemistry

n(u)=36

n(b)=19

n(c)=16

n(bun)=5

n(bnn)=x

19-x+x+16-x+5=36

19+16-x+5=36

19+16+5-x=36

40-x=36

40-36=x

x=4

:.4 students read both biology and chemistry

number of students who read only chemistry is

16-x

but x=4

16-4

=12

:.12 students read only chemistry

Answer 2

11 students read both Biology and Chemistry. 5 students read only Chemistry.

The Venn diagram should represent the following information:

There are a total of 36 students in the class.

19 students read Biology.

16 students read Chemistry.

5 students were not allowed to read both subjects.

From the Venn diagram, we can see that:

11 students read both Biology and Chemistry.

5 students read only Chemistry.

14 students read only Biology.

Therefore, the answers to the questions are:

How many students read both Biology and Chemistry?

11 students read both Biology and Chemistry.

How many students read only Chemistry?

5 students read only Chemistry.