Science & Mathematics - 26 July 2007

A Newspaper resporter described the old rules for the telephone area codes by writing

"possible area codes with 1 or 0 in the second digit (Excluded: codes ending in 00 or 11, for toll-free calls, emergency services, and other special uses.)"
Codes beginning with 0 or 1 should also be excluded.

How many different area codes were possible under these old rules?

2007-07-26 21:00:19 · 2 answers · asked by 56984 2 in Mathematics

The teacher asks each one of the student in a class to write a 2-digit number on the board. The teacher claims that at least three numbers whose digits have the same sum. How many students has there to be in the class in order for the teacher to be correct?

2007-07-26 21:00:08 · 14 answers · asked by Venezia 2 in Mathematics

2007-07-26 20:52:57 · 9 answers · asked by aelgani n 1 in Physics

where can we get propolis to buy

2007-07-26 20:51:49 · 2 answers · asked by Nana S 1 in Medicine

2007-07-26 20:44:16 · 15 answers · asked by Anonymous in Other - Alternative

I confused with this equation. I cannot solve this problem even using calculator. Plz show me steps to solve with calc.

Q=20K^0.1L^0.9 where K=20 and L=50

2007-07-26 20:38:14 · 5 answers · asked by chirag p 1 in Mathematics

2007-07-26 20:36:30 · 11 answers · asked by Anonymous in Astronomy & Space

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2007-07-26 20:31:29 · 5 answers · asked by iwan s 1 in Mathematics

i cant solve this word problem please help me,thanks.

Ethane gas, C2H6, burns in air (i.e., reacts with the oxygen in air) to form carbon dioxide and water:
2C2H6 + 7O2----> 4CO2 + 6H2O

a) How many moles of O2 are needed for the complete combustion of 20.7 mol of ethane?

b) How many grams of CO2 are produced for each 6.66 g of H2O produced?

2007-07-26 20:30:00 · 4 answers · asked by lulu 1 in Chemistry

Some people helped me with explaining but now please help me with the equations.

1)Dissolve a small pinch of benzoic acid in 2 mL of hot water (discard any undissolved solid). Add 10% NH4OH til slightly basic to litmus. Boil of excess ammonia. Add 2 drops of ferric chloride solution. What is the equation?

2)Place 2 drops of acetyl chloride in a test tube. Add 5 drops of water carefully. Give the equation.

3)To 2 drops of anhydride in a test tube, add 5 drops of water carefully. Give equation.

4)Heat about 0.1 g of oxalic acid crystals in a test tube with a delivery tube the other end dipping into lime water. What gas is evolved? Give equation.

5)Repeat #4 using 0.1g succinic acid and fresh lime water. Equation.

2007-07-26 20:28:08 · 2 answers · asked by Anonymous in Chemistry

i am very interseted in space,stars,planets and earth.So i wanted to be an astronomer .but im worried if i would be able to put up with college when i get there.and if i would make it to be an astronomer.

But i love kids and what to keep them healthy and help kids all over the world but im not that interested in it and i want to make my parents proud.


should i be a childs doctor for the kids and my parents sake

or should i be an astronomer for my sake and to forfill my dream and for the earths sake.

so should i choose kids of the future or People of the world?

2007-07-26 20:23:38 · 10 answers · asked by Anonymous in Astronomy & Space

Two cups are filled to the same level with water. One of the two cups has a ping pong ball floating in it. Which of the two cups weighs more?

2007-07-26 20:20:44 · 7 answers · asked by Anonymous in Physics

If they do give off microwaves signals does that mean they are harmful?

2007-07-26 20:15:10 · 2 answers · asked by Riki 2 in Engineering

shadow person?
I think that I may have, years ago..and here I just thought that it was a "house protective demon" or something like that!!
It didn't move...but, it scared me soooo badly that I couldn't scream, or move! I am really hoping that I don't have to see that again,.,...ever!!

What about you all? What did or have you seen, that was "really there" and you just couldn't explain it!?
What did YOU do?

thanks!

2007-07-26 20:14:54 · 17 answers · asked by Anne99 2 in Paranormal Phenomena

2007-07-26 20:12:04 · 3 answers · asked by Anonymous in Engineering

how many different lucky numbers are there?

2007-07-26 20:03:39 · 4 answers · asked by Answer-er-er 3 in Mathematics

on August 27th at 12:30 am? Marz is supposed to be VERY close to Earth then! I can't wait to see it! Just wondering if you all heard anything of it....

2007-07-26 19:45:36 · 12 answers · asked by Anonymous in Astronomy & Space

2007-07-26 19:30:58 · 12 answers · asked by blehbleh 1 in Mathematics

I'm interesting in become some type of engineer. A few people have tried to explain but they all say something different. I'm interesting in building skyskrapers or modern buildings. I've heard of demolition engineers but I don't know if that's a true profession. Feel free to im me for explanations! (forcefeedtheskinnies)

2007-07-26 19:29:15 · 5 answers · asked by forcefeedtheskinnies 1 in Engineering

2007-07-26 19:25:08 · 11 answers · asked by Answer-er-er 3 in Mathematics

2007-07-26 19:12:47 · 3 answers · asked by Freesumpin 7 in Astronomy & Space

here i have uploaded a table

http://img512.imageshack.us/my.php?image=scan0002pl2.jpg

i dont understand the meaning of the problem statement

"Each university is represented by three of its best colleges".

what it means in this context ?

does it mean universirt1 has 3 colleges . university2 and others also have 3 collges ....then there should have 3x5 = 15 colleges !!

I think i am understanding it wrongly.

someone please help me to understand the meaning of that problem-statement

2007-07-26 19:12:40 · 4 answers · asked by calculus 1 in Mathematics

2007-07-26 19:11:10 · 1 answers · asked by Divine C 2 in Engineering

how do you calculate the mass of the following. (Avogadro's number = 6.022E23 particles/mol).

oxygen in 5.52E+22 molecules SO3

2007-07-26 19:05:02 · 3 answers · asked by Anonymous in Chemistry

2007-07-26 19:02:40 · 3 answers · asked by Previn G 1 in Physics

age be 3/5 of her uncle's ?

i-Maths :-

2) In 6 years' time, Alvin will be 30 years old and his younger brother's age will be 1/3 of his. In how many years' time will his younger brother's age be 3/5 of his ?

2007-07-26 19:02:25 · 6 answers · asked by Lim S 3 in Mathematics

An amphibious car of sorts that would travel on ice, and if fell through would be able to (using hydraulic rams) get out of the ice, or float and sail in it, had it been thin enough.

Possible?

2007-07-26 19:01:11 · 2 answers · asked by Raz 1 in Physics

Two hoses, one of 2.0cm diameter, the other of 1.0cm diameter are connected one behind the other to a faucet. At the open end of the hose, the flow of water measures 1.0L/min. Through which pipe does the water flow faster?

2007-07-26 18:55:37 · 1 answers · asked by Anonymous in Physics

It says that the turquoise will turn pale or white when someone wears it and dies. Not sure if it's true, but could right? SOmeone want to prove it? Dunno where the article is, but found it on someone's xanga

2007-07-26 18:54:27 · 6 answers · asked by Anonymous in Earth Sciences & Geology

When clean and dry, sand and even most rocks have no smell. Why does something that has been created (over lots of years) from decaying matter and dirt smell so clean?

2007-07-26 18:46:09 · 5 answers · asked by Puss in Boots 4 in Earth Sciences & Geology