Question

Out of 60 students of 5 study mathematics and 20 study mathematics and chemistry both.Then how many students study only chemistry

Answer 1

Answer:

Total student = 60

Maths = 5

Both = 20

Step-by-step explanation:

Chemistry = 60 - 25

= 35

Answer 2

Given :

Number of students = 60

Number of students study mathematics = 5

Number of students study both mathematics and chemistry = 20

To find : Number of students study only chemistry = ?

Solution:

n(M) = 5

n(M∪C) = 60

n(M∩C)= 20

So, we get :

$n(M\cup C)=n(M)+n(C)-n(M\cap C)\\\\60=5+n(C)-20\\\\60=n(C)-15\\\\60+15=n(C)\\\\75=n(C)$

So, the number of students only chemistry is given by

$n(C-M)=n(C)-n(C\cap M)\\\\n(C-M)=75-20\\\\n(C-M)=55$

Hence, there are 55 students who study only chemistry.