22 September 2018

The continental divide in my knowledge

Once I finished memorizing all the African countries, I asked myself if I could extend that to learn all the country names in the world. Naturally, I started by Googling “How many countries are there in the world?”

You would think it should be a straight forward answer. Far from it. The definition of a “country” is not as clear cut as I had thought it would be. There are countries that the UN recognizes. Then there are are completely autonomous areas with their own government and no control from outside – but they do not go for UN membership (e.g. Cook Islands). Kosovo is not a recognized country by UN, but it competes in the Olympics as a nation.

In fact, if I have this right, there are 195 sovereign states recognized by the UN, 201 partially recognized states, 204-207 de facto sovereign states, 206 Olympic nations, 211 FIFA countries and get this – 249 countries that have their own ISD (country code for telephone numbers) codes!

Anyways, finally memorized the names of all the nations recognized by the UN. Trying to understand the definition of continents was a trifle more tricky. Learnt some really interesting tidbits about continents. See how many of these you knew:

1. Which continent is Greenland in?
2. Which is the continent with the most number of countries?
3. Which is the continent with the least number of countries?
4. How many countries have contiguous area that straddles over two different continents?
5. This one is specially for my friends who live in the USA like me. How many countries in our continent?

9 September 2018

Sunday morning puzzle

Sunday morning puzzle

I was led to this problem by my great friend Karthik’s son – Aadi – who is a whizkid in logic and numbers problems. I need to spend more time with him just to learn about more puzzles.

This problem was published in New York Times as the Tax Man Problem. I have changed the description a little – but the problem is the same.

You and I sit across a table with twelve cards marked 1 thru 12 between us. Following are the rules of the card:

1. You pick a card.
2. I get to pick all the factors of that card that are remaining on the table.

(To explain, if you picked card marked “10” first, I pick up “1”, “2” and “5”. )

3. We continue with this.

(To explain, now if you pick “8”, I pick “4”. Remember “1” and “2” are already gone in the previous move)

4. You CANNOT pick a card if there are no factors of that card left for me to pick.

(To continue with the above example, you cannot pick “11” now, because its only factor “1” is already gone and I am left with nothing to pick)

5. Finally, when you have run out moves (there is no card left for you to pick without violating Rule 4 OR there are no cards left on the table), the game is over.
6. Now we add up our cards.

Whoever has higher total, wins.

To finish off that example:

You: 10
I: 1,2,5
You: 8
I: 4
You: 12
I: 3,6
You: run out of moves (you cannot pick any of the remaining cards – 7,9,11 – since they have no factors left)
I: 7,9,11

Your total: 10 + 8 + 12 = 30
My total: 48 . I WIN!!

Question: What is the highest total you can get and win?

8 September 2018

African capitals

Continuing with the learning of the Dark Continent, managed to nail all the African capitals in two different tests in first chance.

Forget my knowledge in Geography… trying to memorize names everyday for about 20 minutes might be a good way to stave off age-driven memory loss issues.

Also, who knew there are cities called Ougadougou, N’Djamane, Mbabane or Bujumbura? That was a lot of fun!

Ramesh Krishnan, your turn now. (For the rest of the readers, Ramesh beat me on the African country test by almost a whole minute!)

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1 September 2018

On the seventh day, he… took the test

After studying about African countries (just their location and their names – no more, yet) and Nikita and I doing the jigsaw puzzle every afternoon for fun, finally, I was ready for the test on Sporcle.

In the very first round, managed to name all the countries and their locations. In 4 minutes and 09 seconds. Now I am very scared to try it out again. I am deeply aware of the fact that me score can only go downhill from here 🙂

The 4 minute plus probably is not a stellar time but I am telling you – Africa does not make it easy on you with the country names. It has Guinea, Guinea-Bissau and Equatorial Guinea. I think their Department of Naming Diversity was headed by an ex-Atlantan (we call all our roads Peachtree). There is a Republic of Congo and then to make it more interesting, there is a Democratic Republic of Congo.

Funny part is Gambia – which foresaw that other countries might also call themselves with similar names – made the preemptive move of putting the definitive article in its name. It calls itself “The Gambia”! The kicker? When Portugal ruled it, it was called “A Gambia” !!!

Next round of studies … capitals of all those countries. This is going to be much more difficult since there is unique shapes and locations to visually remember like I could for the countries.

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23 August 2018

This week Thursday puzzle

Bill Hubbard, what can I say – 3 different airlines, 6 flights, 4 different cities this week. You know who to blame for one more puzzle 🙂

Anybody who works out the answer, feel free to post the answer only in the Comment section. Send your logic as a personal message to me. Do not write your logic in the Comments section.

Now to the puzzle.

In a Polynesian island, girls are highly preferred as a child. This has led to a strange practice over the years among couples who are trying to have a baby. If they have a baby boy, they keep trying to have another baby in the hope that it will be a girl. If it is a baby girl though, they stop having any more babies. Of course, given any birth, the probability of having a baby boy or baby girl is half and half. So, they keep having more babies as long as they are all boys and stop moment they have a girl

As a result, there are couples who have one girl, couples who have one boy and one girl, couples who have two boys and one girl, couples who have three boys and one girl (and the girl is always the last baby they have) but no couple with two girls (or more).

Here is the question: Over a longer period of time, what is the likely ratio of boys and girls in the island?

18 August 2018

A weekend puzzle

In a class there were 40 students with roll numbers 1 thru 40. One day, the teacher got them all to sit around in a circle sequentially in the order of their roll numbers (1 thru 40). (Of course 40 sat next to 39 on one side and 1 on the other). She then gave a wand to student number 1. What the student had to do is turn towards the next student (which would be #2) and tag him/her with the wand. Upon tagging, the tagged student steps back and is out of the game and the wand is then handed to the next student – which would be student #3 in this case

Now student #3 does the same thing – tags student #4 who steps back and is out of the game and then the wand is handed to #5.

This keeps going on and on (in circles) till only one student is left.

Can you figure out which student was the last one left?

5 August 2018

Puzzle: The horse race problem

A friend of mine from Australia sent me this problem yesterday. It turns out to be a very interesting puzzle. See if you can get it. Feel free to send in your answers or attempts in the Comments section and I will try to respond.

In a horse race, 25 horses show up to win the gold, silver and bronze medals. Unfortunately for the organizers, there are only 5 tracks available – which means you can race only 5 horses at a time. The owners/jockeys agree that their horses will have to run multiple times to decide the first, second and third ranks. You can assume that a horse can run any number of times and always retains the same speed anytime it runs.

Here is the question: What is the minimum number of races you have to have to decide the gold, silver and bronze medalist?

10 June 2018

Puzzle: Learning about new countries

When I visited Mongolia this time, Roger introduced me to a book “Tuva or Bust”. If you have not read that book, chances are you would not know that there used to be a country called Tannu Tuva (kind of northwest of Mongolia). Or that the Noble prize winning physicist Richard Feynman never fulfilled his wish to visit that country in spite of years and years of efforts.

That got me thinking about how little I knew about countries. Actually, my knowledge of countries is pretty much stuck with what I had learnt (and how the world looked) during my school days – so let’s say mid 80s. Even then, I was terrible with countries from Africa.

After coming back from Mongolia though, I did make some effort to learn about the new countries that have formed in the last two decades or so. Previously, I could not even place them in the world map. Now I can. I am still struggling with the names of their capitals though.

I cannot give you this puzzle without ruling Sharmistha Kolay out of this game. She is a whiz kid when comes to geography. Not only can she name each and every country by continent and place them in a world map, she can name their capitals and …. get this… tell you what their flag looks like. I have never met anybody like her.

So here is the puzzle… I will name some newly formed countries… and you will have to name their capital. Try it by yourself. And then Google them up. How many did you get?

A. Countries that formed when USSR broke up:

-> “The Stans” in Asia
1. Tajikistan
2. Turkmenistan
3. Kyrgyzstan
4. Uzbekistan
5. Kazakhstan

-> Between the Caspian Sea and the Black Sea
6. Azerbaijan
7. Armenia
8. Georgia

-> In Europe
9. Ukraine
10. Moldova
11. Belarus
12. Latvia
13. Lithuania
14. Estonia

B. Countries that formed when Yugoslavia broke up:

15. Serbia
16. Bosnia Hercegovina
17. Montenegro
18. Macedonia
19. Kosovo
20. Slovenia
21. Croatia

C. Other new countries

-> Africa
22. South Sudan
23. Eritrea
24. Namibia

-> Asia
25. East Timor (Timor-Leste)
26. Palau

-> Europe
27. Slovakia
28. Czech Republic

BTW, I could not even reach the one-third mark!!! How many did you get?

Finally for the bonus question… and maybe we will open this up to Sharmistha even… Have you heard of a country called the Republic of Artsakh? Look it up!!

27 April 2018

An interesting problem to solve…

Imagine this… I am on a 15 hour flight from Doha to Atlanta. There is a TV screen with a lot of movies but I do not watch movies. There are my favorite shows like Big Bang Theory, Friends etc but how many times can you see the same 10 episodes? Remember, I had to take a 15 hour flight going to Doha too. And I do this multiple times a year.

So, I was lazily looking into the progress of the plane on the map of the globe. It was showing on the globe where we were and our trajectory. Notice the picture on the top half. As you can see, we were somewhere around the New Foundland area in Canada.

Here is the problem:
I was trying to ascertain roughly where the north pole was in that map. Just to see how close did we go to the north pole. The problem is in this map, all of Greenland and the Arctic area is shown as one white blob.

I also want to let you know that the screen is a smart one like you have in iPad. You can use one finger to go left and right and using two fingers, you can make the globe rotate (on any axis – depending on how you swipe both fingers). As an example, I used my two fingers and slid them up and a little to the left. As you can see in the picture in the lower half, the world rotated on a horizontal axis and rotated to the left. You can notice how North America moved up and then the North pointer in the compass turned by 90 degrees.

The point is, using the two fingers, you can turn the globe on any axis as you want (going thru the center of the earth).

Using this, can you pinpoint where the North Pole is?

21 February 2018

Another puzzle. Arranging digits

Do not write the answer in the Comments section. If you get the answer, simply message me on FB or write in the Comments section that you got it (without actually giving away the answer).

Can you come up with a 8 digited number where the digits are 1,1,2,2,3,3,4,4 and the following are true:
There are exactly 4 digits between the two “4”s in the number.
There are exactly 3 digits between the two “3”s in the number.
There are exactly 2 digits between the two “2”s in the number.
There is exactly 1 digit between the two “1”s in the number.

So, 12344321 cannot be an answer since there are 6 digits between the “1”s, 4 digits between the “2”s etc etc etc.

What is the number? (Hint: There are two answers)