Question

In a examination 80 student secured first class marks in english or math. Out of this 50 student obtain first class marks in math and 10 student in English and math both. How many student secured first class marks in English only​

Answer 1

Answer:

Step-by-step explanation:

In order to solve this question, you need a little concept of Venn diagrams. It'll make the sum simpler.

In the image attached you can see the Venn diagram.

Acc.to question,

no.of students scored first class in maths only = 50.

no.of students scored first class in both maths and english = 10.

Let's assume no.of students scored first class in english only = x

Therefore,

50+10+x=80  (Since in total 80 students scored first class marks in mathematics or English)

or, 60+x=80

or,x=80-60

or,x=20(Ans).

Hence 20 students got first class marks in English only.

Read more on Brainly.in - https://brainly.in/question/4404472#readmore

Answer 2

Soln
n(U)= 80
n(M)=50
n(MnE)=10
n(E) = Let x
no(E)=?
From venn diagram,
n(u)= n(M)-n(MnE)+n(E)-n(MnE)+n(MnE)
80=50-10+x-10+10
80=40-x
x=40
Now,
no(E)=x-10
=40-10
=30