I did my 11th and 12th standard studies in a residential school called DAV Public School in Purulia, West Bengal. One evening I accompanied some of my classmates who went to a shop to buy some stuff for themselves. I didn't have anything to buy. So, I was standing quietly at one corner. An old man mentioned as O below struck up a conversation with me. S is me.

O: So, are you a student?
S: Yes.
O: Which school do you study in?
S: DAV Public School.
O: Ok, what's your name?
S: Susam Pal.
O: Oh, so you are a Bengali.
S: Yes.
O: Which caste do you belong to?
S: I don't know.
O: You don't know? What kind of Bengali are you?

Here's a puzzle I came up with when a false fire alarm went off in our office. In the following dialogue, R is my colleague and S is me.

S: Hey! There's a fire alarm. Run!
R: You run.
S: No, I am a true programmer. My job is to keep programming even at the
face of death.
R: Really?
S: Yes, just like … Oh, wait! Let me ask this as a puzzle. There
is at least one profession in which you can not quit your job even if
there is fire. The job requires you to keep working even though there is
fire and you as well as your entire team is going to die.
R: Firefighting?
S: No, firefighters may have the option to exit a building on fire if
the fire poses danger to their lives. I'm talking of a profession where
there is no such option.
R: Hmm.

Here is a practical problem from a factory. There are illiterate workers who can not identify digits and do not know in which order they occur. They are supposed to fill cans with a certain weight of a given material. With a beam balance this is easy since a worker can place the required weight in one pan and keep pouring the material in another pan as long as the beam doesn't appear to be balanced. However, this factory uses digital weighing scales. What do you think is the easiest way to train the workers to do their job with a digital weighing scale apart from teaching them how to count or altering the digital weighing scale?

Note that the workers may be asked to fill a can with 3.1 kg of material, i.e. decimal fractions may be involved.

Update: Prunthaban's solution in the comments was successfully implemented at OCL India Limited, Rajgangpur. Thanks, Prunthaban.

Many people who go on vacation set up auto-replies in their email clients that automatically respond to emails sent to their inboxes and inform the senders that the recipient is on vacation.

Often they promise in their auto-replies that they would revert back to me after they are back from the vacation. Some of them promise to revert back to my emails instead.

I've never understood how they could revert to being me or my emails because they never were me or my emails. They were always themselves right from their birth. However, even with this confusion, I've always eagerly waited for them to return from vacation so that I could watch them transform into me or my emails. But they have never kept the promise they make in their auto-replies. They have never transformed into me or my emails.

I asked Pragyan, a good friend of mine, whether this is really possible and she told me that in this century when science has advanced so much that biologists can create synthetic life, it shouldn't be surprising that other people can transform into me or my emails. She might have a point there but without any evidence, this whole notion of a person turning into another person or an email seems like a big hoax to me.

Sharing some very inspiring words from the commencement address by Steve Jobs delivered on June 12, 2005 at Stanford University.

The first one is from his story about "love and loss".

You've got to find what you love. And that is as true for your work as it is for your lovers. Your work is going to fill a large part of your life, and the only way to be truly satisfied is to do what you believe is great work. And the only way to do great work is to love what you do. If you haven't found it yet, keep looking. Don't settle. As with all matters of the heart, you'll know when you find it. And, like any great relationship, it just gets better and better as the years roll on. So keep looking until you find it. Don't settle.
The next is one from his story about "death".
Your time is limited, so don't waste it living someone else's life. Don't be trapped by dogma - which is living with the results of other people's thinking. Don't let the noise of others' opinions drown out your own inner voice. And most important, have the courage to follow your heart and intuition. They somehow already know what you truly want to become. Everything else is secondary.
The complete video recording of the speech can be found here: YouTube - Steve Jobs' 2005 Stanford Commencement Address