Try this one. It is not as simple as it might sound but not as complicated either.

You have six identical balls except two are painted red, two are painted blue and two are painted white. You know one ball of each color weighs 10 pounds and one ball of each color weighs 11 pounds. (So each color has one lighter ball and one heavier ball).

You have a scale and pan balance but no weights. Only the balance and the six balls.

What is the minimum number of weighings you have to do to determine which are the heavier balls and which are the lighter balls?

I came up with this puzzle on my flight this evening. Therefore, my solution is not fully vetted. I will put my solution and then hopefully some of you will either show a better solution or vouch for mine. As of now, I am going to post the puzZle and hit the sack. I will check your answers tomorrow.

You have a traditional weighing scale and pan balance – you know where you can put weights or stuff on any of the two sides… You also have the following weights (don’t worry about the units): 1, 10, 100 and 1000.

The question is – how many different weights can you weigh combining the above weights?

I can’t find the answer to the question I had for myself today. I Googled but still can’t find it. The question is – Which river forms the longest international boundary?

Speaking of rivers and international boundaries, what is your guess about which river crosses the maximum number of international borders? In fact, it flows thru as many as 10 countries.

Here is another interesting trivia question – there is a point close to the above river where three country borders meet. At that point is a picnic table that is shaped as an equilateral triangle! The sides are parallel to the borders! There are three benches on the three sides with the appropriate country’s flag imprinted on their side. You can eat your food and jump from country to country without needing any visa!! Want to guess what those countries are?