Answer:
The irony in the arrest of Mrs. Bamjee is that she was working to help the colored people to be free from the racially discriminatory system of Apartheid but was arrested by two colored policemen, the very section of people she was working to help.
Step-by-step explanation:
Irony is when something that is expected did not happen or occur but the opposite instead happens. This rhetorical device is used to show an event that occurs contradictory to the expected or desired.
In Nadine Gordimer's short story "A Chip of Glass Ruby", Mrs. Bamjee is of Indian descend, but believed in the importance and need to protest against the government's Apartheid policy. To her, the blacks are discriminated against by the whites and she needed to do her bit to help those suffering. So, she did whatever she could to highlight and spread the monstrosity of the discriminatory nature of the Apartheid policy. Ironically, she was arrested by two colored policemen, the very race or group of people she was trying to help.