54 students of class IX are taking part in sports or in music or in both activities. Out of them 9 students are taking parts in both activities. The ratio of the number of students who are taking part in sports to those who are taking part in music is 5:4.
(i) How many students are taking part in sports?
(ii) How many students are taking part in music only?
(iii) Illustrate this information in a Venn-diagram.
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Class 11
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>>Venn diagrams
>>In a survey of 200 students of a school
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In a survey of 200 students of a school it was found that 120 study Mathematics, 90 study Physics and 70 study Chemistry, 40 study Mathematics and Physics, 30 study Physics and Chemistry, 50 study Chemistry and Mathematics and 20 none of these subjects. The number of student who study all the three subject is
Medium
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Correct option is B)
Let M, P and C denote the students studying Mathematics, Physics and Chemistry
And U represents total students
So, n(U)=200,
n(M)=120,n(P)=90
n(C)=70,n(M∩P)=40,n(P∩C)=30
n(M∩C)=50,n(M∪P∪C)
′
=20
∴n(M∪P∪C)
′
=n(U)−n(M∪P∪C)
⇒20=200−n(M∪P∪C)
⇒n(M∪P∪C)=180
⇒n(M∪P∪C)=n(M)+n(P)+n(C)
−n(M∩P)−n(P∩C)−n(C∩M)+n(C∩M∩P)
∴180=120+90+70−40−30−50+n(C∩M∩P)
⇒180=280−120+n(C∩M∩P)
⇒n(P∩C∩M)=300−280=20
Answer:
the process by which green plants and some other organisms use sunlight to synthesize nutrients from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a by-product.