Question

in a class of 32 students each one opted for mathematics are business studies or both 20 students opted for mathematics and 9th Student of the mathematics as well as business studies how many students opted for only business studies​

Answer 1

Answer:

Number of students opted mathematics =n(M)=30

Number of students opted Biology =n(B)=32

Number of students opted both Mathematics and Biology =n(M∩B)=24

Number of students opted Mathematics or Biology =(M∪B)

n(M∪B)=n(M)+n(B)−n(M∩B)⇒n(M∪B)=30+32−24=38

(i) Probability that student opted Mathematics or Biology =nn(M∪B)=6038=3019

(ii) Probability that student has opted neither mathematics nor Biology =1−P(M∪B)=1−3019=3011

Number os students opted only Mathematics =n(M)−n(M∩B)=30−24=8

(iii) Probability of selecting students who opted only mathematics =608=152