Question

Find the number of individuals exposed to Chemical C2 but not chemical C1​

Answer 1

Step-by-step explanation:

Let U= set of individuals suffering from the skin disorder

A= set of individuals exposed to the chemical C

1

B= set of individual exposed to the chemical C

2

Then n(u)=200,n(A)=120,n(B)=50 and n(A∩B)=30

Similarly, B=(B−A)∪(A∩B)

∴n(B)=n(B−A)+n(A∩B)

∵n(B−A)∩(A∩B)=φ

∴n(B−A)=n(B)−n(A∩B)

=50−30=20

Hence, 20 individuals exposed t chemical C

2

but not to chemical C

1