From an IAS interview:
interviewer: "..............so have you stopped beating your wife?"candidate: well sir, i cannot understand how such a personal matter came to your notice?, have you got a private investigator checking on me??

As the prof explained that this type of questions put you in a fix. You say yes and it means you used to beat your wife, say no and it means you are still into beating your wife. The question was meant to surprise the candidate, but the candidate pulled a fast one on the interviewer without being offensive.

the class was about negotiations and how formally and informally we all indulge in it. It was how women in mumbai high rises refused to have fresh vegetables delivered to them because they missed the thrill of bargaining!!

it was also about how Nigerians bargain

scene: you enter a Nigerian shop as you like a dress. the moment you enter the shopkeeper thanks christ"s statue.

Nigerian: Oh Christ be praised, so mas"ter comes to our shop, i am blessed
you: yes that is fine. i like that dress.
Nigerian: Oh master! so many people coem here everyday! but no one but master sees the gem!! it is really a beautiful piece, you have a wonderful choice master. master for you the final price is $50
You: do you have a knife?
Nigerian: yes master, here...
You take the knife and place it next to your heart and behave as if someone stabbed you
Nigerian: master why do you do that?
You: well if you will ask me so high a price, $50, it is like stabbing me in the heart!
And from hereon the real negotiation starts.......you will discus economics, politics and sociology while he will keep slipping in his final price.............and when he says last final price, you know this is how much he will come down and you adjust the price and buy the cloth completing a successful negotiation :)

PS: if you would have agreed to $50, he would have made a face and lost all the fun in selling to you!!

PPS: a friend's input: on the question of beating his wife: no sir, these days i am beating ur wife instead :)