The concept of Yin and Yang are used to describe how seemingly disjunct or opposing forces are interconnected and interdependent in the natural world, giving rise to each other in turn (

A goat is tied on the corner post of a 20×20 ft barn in a flat grass field.

The goat can reach a length of 45 ft at maximum from the corner post

OK, so here we have it: Bilbao’s 4th and final clock challenge.

Our general audience will be pleased because it is entirely feasible for you to come up with an

For the 2nd challange, we had a bit of dropoff.  Nice job to those who were able to figure it out:

It is well known that in commercial advertising of clocks a certain position of the hands is usually shown (see picture above). The reason might be aesthetic, equilibrium, ok shape, smile shape, etc.

Starting today, we have a series of 4 clock puzzles

[click on image to view/print higher resolution picture]

The Totem Pole shape consists of Orange, Red, and Blue blocks. Which volume is the smallest

Ok, this one’s tough. I know there’s a bunch of you out there who love the math type puzzles, and this one’s going to be hard to crack:

The 400 soldiers of the 7th company are ready to march.

A fisherman rowing his boat on a very small lake throws his anchor into the water. Does the water level of the lake rise, fall, or stay the same?

A farmer has 3 square fields shown above, each containing 18, 20, and 26 acres. In order to get a fence around his property, he bought the 4 intervening triangular fields.

Lucy was born on a sunny Sunday in Hong Kong and celebrated her 7th birthday party on a rainy Sunday in Macau. How old was she in 1996?

A list of people who have solved so far:

Hard: Dan, Shawn, michaelC, LaDana,

If the earth should suffer an apocalypse on the first day of a new century, can you say what the chances are that it will happen on a Sunday?

Here’s a neat little math brainteaser:

Zenith let me know of this excellent challenge.  Looks like it should be easy, but it’s not:

What’s the next sequence in this set?

1

11

21

1211

111221

you may submit your answers below in the comment section; will unmask in several days, thanks.