Question

Hey friends !!

A good question from set .

In a class 40% of the students enrolled for maths and 70% enrolled for economics . if 15% of the students enrolled for both math and economics, what % of the students of the class didn't enroll for either of the two subjects ?


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Answer 1

HEYA!!!


HERE IS YOUR ANSWER,


=> n(A ∪ B) = n(A) + n(B) - n(A ∩ B),

=> Where,

> (A ∪ B) represents the set of people who have enrolled for at least one of the two subjects Math or Economics.

> (A ∩ B) represents the set of people who have enrolled for both the subjects Math and Economics.

=> n(A ∪ B) = 40 + 70 - 15 = 95%

=> That is 95% of the students have enrolled for at least one of the two subjects Math or Economics.

=> Therefore, the balance (100 - 95)% = 5% of the students have not enrolled for either of the two subjects.

=> Thus, % of the students of the class that didn't enroll for either of the two subjects is 5%.


HOPE IT HELPS YOU,
THANK YOU.☺️☺️

Answer 2

(1)

The number of students who have enrolled for maths n(A) = 40.

The number of students who have enrolled in both maths and economics = 15.

 = > 40 - 15

= > 25.

The students enrolled for maths = 25.


(2) 

The number of students who have enrolled for economics n(B) = 70.

The number of students who have enrolled in both maths and economics = 15.

= > 70 - 15 

= > 55.

The students enrolled for economics = 55.


Now,

The students who have enrolled in maths + economics  = 25 + 55

                                                                                              = 80.



The students Who have enrolled both = 15.

Therefore the total number of students enrolled = 80 + 15

                                                                                  = 95.


Therefore, the students who didn't enroll = 100 - 95

                                                                      = 5%.



Hence, 5% of the students didn't enroll in either of the two subjects. 


Hope this helps!