There are 2000 individuals with a skin disorder . 120 had been exposed to the chemical `C_(1)`, 50 to chemical `C_(2)` and 30 to both the chemicals `C_(1)` and `C_(2)` . Find the numbers of individuals exposed to :
(i) Chemical `C_(1)` but not Chemical `C_(2)`
(ii) Chemical `C_(2)` but not Chemicals `C_(1)`
(iii) Chemical `C_(1)` or Chemical `C_(2)`.

Answer

(i) `=90`
(ii) `=20`.
(iii) `=140`.