in school there are 30 teacher who teach maths or physical of there ,18 teach maths and 6 teach , both physical and maths . how many teach physics only

in school there are 30 teacher who teach maths or physical of there ,1

1.	in school there are 30 teacher who teach maths or physical of there ,18 teach maths and 6 teach , both physical and maths . how many teach physics only
Answer» <html><body><p><strong>Answer:</strong></p><p>Number of <a href="https://interviewquestions.tuteehub.com/tag/teachers-25555" style="font-weight:bold;" target="_blank" title="Click to know more about TEACHERS">TEACHERS</a> who teach math or physics =<a href="https://interviewquestions.tuteehub.com/tag/n-568463" style="font-weight:bold;" target="_blank" title="Click to know more about N">N</a>(M∪P)=20</p><p></p><p>Number of teachers who teach math = n(M)=<a href="https://interviewquestions.tuteehub.com/tag/12-269062" style="font-weight:bold;" target="_blank" title="Click to know more about 12">12</a></p><p></p><p>Number of teachers who teach math and physics =n(M∩P)=4</p><p></p><p>Find : Number of teachers who teach physics =n(P)=?</p><p></p><p><a href="https://interviewquestions.tuteehub.com/tag/solution-25781" style="font-weight:bold;" target="_blank" title="Click to know more about SOLUTION">SOLUTION</a> :</p><p></p><p>n(M∪P)=n(m)+n(P)−n(M∩P)</p><p></p><p>20=12+n(P)−4</p><p></p><p>20−12+4=n(P)</p><p></p><p>n(P)=12</p><p>hence 12 teacher teach the physics</p><p></p><p></p></body></html>