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?

Category: Puzzles | 2 Comments on Can somebody help me with this simple math problem?
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.

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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.

Category: Puzzles | 4 Comments on Puzzle for this Sunday morning
7 March 2025

Help!! A day later, I still do not have a solution

This is the Wordle problem from yesterday. I tried my usual first word. And hit jackpot with the second word. Got all the five letters but none of them were in the right position.

Then I got distracted. Instead of solving the Wordle problem, my idiotic brain converted it into a math problem. The question I had for myself was – in how many ways can I arrange the five letters (there is no repeat) where none of the letters will occupy the same position as the all yellow row. In other words, how many combinations of LATER can you come up with where the first letter is not L and second letter is not A and …. (you get the drift).

It is MUCH harder than I thought. One hour later, I realized I was getting late for office. Quickly solved the Wordle part and wrote to my nephew in UC Riverside before getting ready for work.

We still do not have an elegant solution. In desperation, I enumerated all possibilities. I have the answer now but do not know how to solve it.

HELP!!

Category: Puzzles | 2 Comments on Help!! A day later, I still do not have a solution
16 December 2024

Geography quiz on land borders

This time the questions are about land borders between countries. See how many you can answer from what you know, remember or even guess before you resort to Google.

1. Which country has the maximum number of countries with who they have land borders? (Hint: there are 2 of them)

2. Of the number of land borders a country can have, what is the most frequent? (e.g. if 13 countries have 3 as number of land bordering countries, 17 have 4, 20 have 5 and there were no other countries in the world – then 5 would be the answer). [Hint: the answer is fairly surprising]

3. We all know that USA and Canada have the longest land boundary (and one that is not guarded by military too!). Can you name the other 4 in the Top 5? [Hint: Russia and China border is NOT one of them!]

4. Which countries have the shortest land border between them? [Hint: It is about 500 feet!!]

5. This one is also very unintuitive. A country can have multiple land borders with the same country. Enclaves or oblasts are great examples of that. Which two countries have the most number of separate land boundaries between them?

Answers posted here.

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19 November 2024

Puzzle from real life – the coffee cleaning

Every couple of months or so, I face this dilemma. If you make your own cappuccino at home, you are familiar with the wand that heats and foams the milk. Now that wand has a head in the end which looks like the picture on your left. This has 4 small holes in the end – see middle picture. This is where the steam comes out from. Now, because it gets exposed to milk, from time to time it needs to be cleaned.

The cleaning instrument is a simple, small sharp needle – see picture on the right. All you have to do is put the needle in each of the four holes, give it a good spin and then at the end, soak it in water.

Now comes the problem. Once I have given one hole a good clean, I go to the next one. Once I am done with that, I get confused which one to go to next. Which one did I already do? Remember, there are no ways to identify a hole and I certainly do not want to put any scratches on the surface. If I do adjacent ones, for all you know, I have been doing the same two all the time. Because you are spinning the head, you are not sure your final orientation is the same the original one.

What might be a couple of tricks to make sure that with only four cleans, I get each one of them only once?

See answer here…

Category: Coffee, Puzzles | 2 Comments on Puzzle from real life – the coffee cleaning
12 November 2024

Now for a quiz on the lakes of the world

Growing up in India, as young students, we had learnt that the two largest lakes in the world were the Caspian Sea and the Black Sea. While trying to study up the lakes of the world this week, I realized that Black Sea is not considered a lake. It is an inland ocean. I wonder what is being taught in India these days.

Also, when looking up the lakes by size, I could not find one particular lake that we had learnt about in India – the Aral Sea. I have now learnt that the whole lake does not exist any more! It used to be the fourth largest lake in the world. Man made irrigation projects have diverted all the river sources and now it is a desert!

See if you know or can guess the answers to the following:

1. What is the country with most lakes? (it has more lakes than the rest of the world combined)
2. What is the highest navigable lake?
3. What is the lowest lying lake?
4. What is the largest lake in the Antarctica? (it is the 16th largest in the world)
5. What is the largest lake with salt water on one side and fresh water on the other?
6. What is the lake which has more species of fish than any other lake?
7. What is the largest lake in Europe?
8. What is the largest lake that is entirely within one country?
9. What is the longest freshwater lake?
and lastly, a weird one…
10. What is the largest alkaline lake? (it is also the largest desert lake in the world)

You can check here for your answers.

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10 November 2024

Sunday morning quiz: Rivers of the world

After memorizing the names of countries, their capitals and currencies (got stuck with the flags with one third done), tying to now learn about the Top 50 Rivers in the world (by length). Learnt some fascinating facts. There are about 10-12 rivers in the Top 50 that I had never heard the name of!!

See how many of these you might get. The answers are posted here.

1. Which is the country that has most number of rivers in it? (The answer might surprise you)
2. Which country has the most number of Top 50 (by length) rivers running thru it? (It is a whopping 11 of them!)
3. Which river runs thru the most number of countries?
4. Which is the largest country with no rivers at all? (It used to have one long time back)
5. Which is the longest river entirely in one country? (Hint: Second longest such river is also in the same country)
6. Which is the river that has the most number of country capitals on its banks?
7. Which river has two country capitals bang opposite to each other on the two banks?
8. Which river (in the Top 50) has a country capital on it that is an anagram of the river name itself (but two different words)?
9. The longest river is the Nile. The widest is the Amazon. Which is the deepest river?

And finally a controversial one… since Guinness Book of World Records withdrew this category. So I am going by the recorded length of all rivers in the world.

10. What is the shortest river in the world? (It is barely 18 meters – yes meters. Apparently, if there is a constant flowing water, it is considered a river. I could find at least 7 rivers that are not even 100 meters long!!)

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