In a class 18 students took physics, 23 took chemistry, 24 took maths, out of them 13 took chemistry and mathematics, 12 took physics and chemistry, 11 took physics and mathmetics. if 6 were offered all the three subjects find :

1. Total number of students in class

2. How many took maths but not chemistrty

3. How many took exactly one of the three subjects

Hi!

 
Let P, C and M denote the set of student who had taken Physics, Chemistry and Mathematics respectively.
 

Cheers!

  • 20

according to the question

6 will be the intersecion of the three subjects

18 students have taken physics 24 math and 23 chem

ans 1) 35 students are there in the class(draw the venn diagram and count all the numbers)

ans 2) n(M-C) = n(MUC)- n(C)

  = 34 - 23

  = 11

ans 3) those who took exactly one subject= 6(of maths) + 1( of physics) + 4 ( of chem)

  = 11

  • 10
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