Question

There are 200 individuals with a skin disorder, 120 had been exposed to the chemical C1,

50 to the chemical C2 and 30 to the both chemical C1 and C2. Find the number of

individuals exposed to

(a) Chemical C1 but not chemical C2

(b) Chemical C2 but not chemical C1

(c) Chemical C1 or chemical C2

(d) None of the chemicals​

Answer 1

none of the chemical it is d