Question

Out of some students appeared in an examination, 80% passed in English, 75% passed in Science and 5% failed in both subjects. If 300 of them were passed in both subjects, how many students were appeared in the examination? Find it by using a Venn-diagram.

Answer 1

Answer:

Let U be the set of those students who appeared in the examination and were survey.

Let E and S be the sets of students who passed in English and science,

respectively.

Given,

n(U)=100%

n(E)=80%

n(s)=75%

n(EUS)=5%

n(EnS)=300

By using the formula,

n(U)=n(E)+n(S)-n(EnS)+n(EUS)

or,100%=80%+75%-n(EnS)+5%

or,100%=155%-(EnS)+5%

or,(EnS)=160%-100%

there for (EnS)=60%

Now,

we know that,

n(EnS)=60%

or,300=60/100×n(U)

or,300×100/60=n(U)

there for,n(U)=500 ans.

Answer 2

Step-by-step explanation:

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