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?

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?