7 July 2026

I am finally hanging up my boots with this game

Many moons back, my friend Mita Basu had introduced me to this game – travle.earth. The whole idea is to travel from Country A to Country B by crossing only land borders. There are some quirks in the game – It thinks of Siachen Glacier as a country, it does not think you can cross from Morocco to Western Sahara by land, and for some reason, it will not let me go from Poland to Russia directly, although I have been to their land border myself (exclave of Kaliningrad).

But I have now reached the 1000 game mark without failing once. And I am ready to move on to my next geography game. First, I have to dig through my messages from Mita. About a month ago, she sent me another game that I haven’t opened yet!

If you want to learn about country boundaries, this is a great game to try.

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28 June 2026

Sunday morning puzzle

Which of the following statements – if any – is/are true? How do you logically work it out?

1. Exactly one statement in this list is false.
2. Exactly two statements in this list are false.
3. Exactly three statements in this list are false.
4. Exactly four statements in this list are false.
5 Exactly five statements in this list are false.
6. Exactly six statements in this list are false.
7. Exactly seven statements in this list are false.
8. Exactly eight statements in this list are false.
9. Exactly nine statements in this list are false.
10. Exactly ten statements in this list are false.

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6 October 2025

What does “SOS” stand for?

Here is one of the interesting things I learned while picking up Morse code. I can’t believe I have lived all my life without realizing this.

What does the term “SOS” stand for? Growing up, I always thought that it stood for “Save Our Souls”. I believe I first heard this while reading about the story of the Titanic. Some think of it as “Save Our Ship”.

It turns out that “SOS” is not an abbreviation at all. About 75 years after Morse code was created, around the start of the 1900s, the Germans helped set a universal distress code: SOS. They chose it because its Morse pattern [… — …] was easy to recognize. Before SOS, other distress signals were used, with “CQD” being the most common.

So, SOS does not stand for any English phrase. And even if it did stand for something, it would have been very likely a German phrase!

Did you know that?

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22 August 2025

Why is my math not matching with ChatGPT?

I was driving back from the airport when I got a call from my old buddy SK and his son. Apparently, they were stuck on a math problem. What I understood is this:

SK’s son and his friend are trying to get two tickets to a concert. (He told me the name of the concert but of course, that was all Greek to me). The organizers are opening 50,000 slots you can apply to. And they will pick 4,500 of them as winners. In other words, there are only 4,500 seats available.

SK’s son and his friend bought 25 slots.

Question was what is the probability that the two friends would be able to go to the concert?

Apparently ChatGPT was saying 90%. SK’s intuition was far lower than that. His son felt that it made sense. So, over the phone we worked out the approach and agreed it will be a high number.

I got a message yesterday from SK that his son and his friend are indeed going to the show!

This early morning, curiosity got the better of me and I sat down with paper and pen to figure out what the probability would be.

Now, I am stumped! My answer is very different from what SK and his son reported as ChatGPT’s response was.

What do you think is the probability?

Answer published here

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18 August 2025

Triangle and 9 digits puzzle

This puzzle comes from my good friend Amrith.

Fill the three vertices and two spots on each side of the triangle with the numbers 1 thru 9 (using each only once) such that each side adds up to 20.

Multiple solutions are possible.

What approach did you use (other than simple trial and error)?

Answer posted here: https://www.rajibroy.com/2025/08/22/answer-to-triangle-and-9-digits/

21 June 2025

Can somebody help me with this simple math problem?

I thought it to be a fairly simple problem. Now I am stuck. I was reading a book that talked about organizational efficiency. It talked about 3 parameters. Each parameters can take the value of 1 thru 10. So, there are 1000 combinations.

It is at this point, I got totally distracted. The quick thought that came to me mind was how many different products can I get? And ever since, the book be darned, I cannot get my mind off it.

So, to repeat, there are three spots. You can fill each one of them with a number 1-10. So, you get 1000 possibilities. If you take the product of those 1000 possibilities, you will get 1000 numbers. But there will be repeats. For example,(1,2,3) (1,3,2) (2,3,1) (2,1,3) (3,2,1) (3,1,2) (1,1,6) (1,6,1) (6,1,1) will all give 6 as the product.

How many distinct products can you have?

11 June 2025

Vexillology quiz

These days, I have found a great way to learn more about country flags. My friend in office – Danny – is a wizard at this. He asks me questions. I get stumped and then I learn. I come home and learn a few more countries and go back and ask him next day. He answers them without even blinking. My upside is that in the process, I am learning!!

There is another friend of mine Sharmistha – in Houston – who is equally adept in world flags!

Someday, I am going to be like them. Right now I am grinding thru it – one flag at a time…

Here are some interesting things I have learnt…

1. Most all flags are rectangles. However, 2 countries have square flags. Can you name them?

2. Here might be something most people know. Which country has a flag that is neither rectangle nor square?

3. What is the most common color in all the country flags? It is found in a whopping 75%+ flags!

4. What is the most rare color in country flags? How many countries have them?

5. Which country has had the most number of flags?

6. What was the least amount of time that a country flag survived before it was substituted?

7. Which country has the oldest continuously used flag? Celebrating 400 years this year, in fact!

8. How many countries have the front side and the reverse side of the flag different from each other?

9. In the 1936 Summer Olympics, two countries showed up to compete and realized they have the same flag! Next year one of them made an alteration to their flag. Which two countries were these?

10. Many countries have images of arms – often symbolising their struggle and sacrifice for independence. Saudi Arabia’s for example, has a sword. But there is one country that has a AK-47 on its flag!! Can you name it?

Answers posted here.

9 March 2025

Puzzle for this Sunday morning

Take 18 matchsticks and arrange them to form the number 508. I realized that we do not have matchsticks in our home and certainly, we do not have 18 gaslighters – so, resorted to powerpoint to make the picture.

Now, the question is by repositioning two sticks (any two sticks of your choice), what is the highest number you can get? Post your answer in the comments section.