3x3 Magic Square solution

Surely you've come across magic squares. Here's a 3 x 3 magic square. It's really easy to solve and remember.

2 9 4
7 5 3
6 1 8


Here's how i remember the order of the numbers in an empty box:
The even numbers 2, 4, 6, 8 take up each corner of the box with 5 in the middle of the box. The odd numbers take up the remainder empty spots.
Keeping in mind that each row/column/diagonal adds up to 15, it should be pretty easy to figure out which spots the odd numbers belong to since we've already filled up 5/9 of the box.


Perhaps you're wondering why each side should add up to 15. Adding up all the numbers from 1 to 9 will give a result of 45. Since the additions involves 3 numbers, divide 45 by 3 and you get 15. 15 is therefore the average sum of the 3 numbers you add up. This rule can also be applied to other magic squares.

Beyond Human Frequency - Snapple "Real Fact" #48

Did You Know?

Fact: Cats can hear ultrasound.

Ultrasound is the frequency of sound waves greater than what the human ear can hear (approximately 20kHz). Cats have an approximate hearing range of 45Hz - 64,000Hz compared to 65Hz - 20,000Hz of a human hearing range.

*Infrasound is any frequency below the average human hearing range.

The Straight Dope and Real Facts

I've been drinking Snapple recently and i've kept the caps containing "Real Facts". Every cap has a different fact and SO, i'm going to keep track of what i have collected here and perhaps do some extra read up regarding the facts.

As i was surfing the web, i came across this website The Straight Dope.com. It's a website (by a person called Cecil Adams) that contains MANY questions and answers and some other random bits of information that may intrigue you. Claiming to be the smartest human on Earth, why not go check out what he has to offer you?

Pink Flamingos - Snapple "Real Fact" #11

Did You Know?

Fact: Flamingos turn pink from eating shrimps.

Shrimps contain red pigments classified as carotenoids which is found in carrots too! A lack of carotenoids in the diet of a zoo-kept flamingo may turn a flamingo white.

Esters

Question: Work out the number of esters with the molecular formula C4H8O2. - passerby

My reply: Esters have the functional group R-O-CO-R'. My drawing out the compound and permutating the number of ways the functional group can fit into the compound, this is what I get.
By inserting the functional group between the 3rd and 4th carbon atom will yield the same structural formula as (1). Hence, there're only 2 different esters resulting from the C4H8O2 formula. ;)