Mathematics - 26 September 2007

A commerical freight carrier is flying at a constant speed of 400 mi/h and is traveling 4 mi east for every 3 mi north. A private plane is observed to be 210mi due east of the commerical carrier,traveling 12 mi north for every 5 mi west.If it is known that they are on a collision course,how fast is the private plane flying?

Ok so when i tried the problem out..., the freight has a slope of 4/3;The private plane 12/-5;The freight is traveling at 400mi/h; and the we need to know the plane; so maybe i try putting y=mx+b for both making them equal to find the speed? I got lost trying to find speed.Help?

2007-09-26 16:25:44 · 1 answers · asked by Krumpits&Tea☺ 2

why is the rule of divisibility of 7 not in math textbooks

2007-09-26 16:22:44 · 3 answers · asked by suzy 1

A company is decreasing the amount of tuna sold in a cylindrical can by 10%. The cans will have the same height but a smaller diameter. By what percent should the diameter decrease in order to accomodate the change?

2007-09-26 16:12:12 · 2 answers · asked by Anonymous

2007-09-26 16:09:28 · 1 answers · asked by greatestfan84 1

2007-09-26 16:07:56 · 2 answers · asked by Vicky 2

Solve for x
x/2 & x/5 are fractions

2007-09-26 15:53:45 · 11 answers · asked by Abiku 6

Here's a nice little problem distantly related to some work I did way back when for my honours thesis.

In ring theory, an idempotent element is one which is its own square. In a ring with unity, 0 and 1 are always idempotents, but there may or may not be other idempotent elements.

Now the product of idempotents is not necessarily an idempotent. In my honours thesis I was concerned with characterising the elements that could be expressed as the product of idempotents. Here's a little problem relating this to the simple ring Z_n (n any integer ≥ 2).

a) Prove that in Z_n, the product of two idempotents is also an idempotent.

b) If n = p^r where p is prime, show that the only idempotents of Z_n are 0 and 1.

c) If n = pq where p and q are distinct primes, show that Z_n has exactly four idempotents and characterise them.

d) For arbitrary n ≥ 2, characterise the number of idempotents in Z_n in terms of the prime power factorisation of n.

2007-09-26 15:53:24 · 2 answers · asked by Scarlet Manuka 7

The following sets of three numbers each form a word. Put the words together to find a question, and then submit the answer to that question:

(1,4,45) (2,7,5) (6,1,11) (24,3,47) (16,1,6) (13,9,5) (94,3,27) (258,2,41)?

What is the answer?

Hint: The first word is "What".

2007-09-26 15:51:15 · 6 answers · asked by Andrea B 1

I have tried really hard but can't figure these problems out:

1) A coin bank contains 30 coins, all dimes and quarters, worth $5.70. Write a system of linear equations to represent this situation. How many dimes and how many quarters are in the bank?

2) You have $25 to spend on picking 21 pounds of 3 different types of apples in an orchard. The empire apples cost $1.40 per pound, the red delicious apples cost $1.10 per pound, and the golden delicious cost $1.30 per pound. You want twice as many red delicious apples as the other two types combined. How many pounds of each type of apple should you buy?

3) solve for a: S= a(1-r^n)
--------------- (divided by)
1-r

If you could help I would appreciate it sooo much!!!

2007-09-26 15:50:07 · 3 answers · asked by chocolatelover2292 2

2007-09-26 15:48:02 · 9 answers · asked by Anonymous

I have an assignment and i got stuck on this question.... please help me if you can.... all what's required is a small pseudocode for the problem....

Write an algorithm that computes the length of the third side of a right triangle given the lengths of the other two sides.

Input: x,y (the lengths of two sides), and w (if w = 0, x and y are the legs; if w = 1, either x or y is the hypotenuse)
Output: z (the length of the third side)

2007-09-26 15:39:02 · 2 answers · asked by abdul a 2

A rope 8 meters long is to be cut so that hte parts reflect the ratio 5:4. How long should each part be?

2007-09-26 15:35:16 · 3 answers · asked by Fiebelle MAe P 1

2007-09-26 15:33:49 · 12 answers · asked by debbie r 1

2007-09-26 15:32:51 · 8 answers · asked by Abiku 6

2007-09-26 15:30:44 · 2 answers · asked by C7S 7

Derivative: y = 2 [e^(-x)] * x

Short way; having a lot of trouble with this section.

If it's not too much trouble can you explain how to get the answer?

2007-09-26 15:27:39 · 2 answers · asked by Stacy B 3

2007-09-26 15:26:26 · 10 answers · asked by Abiku 6

ok so my science teacher told me to find the answer this but i have no idea how...
ok so the problem goes
lusia conducted an experiment to determine the relationship between distance and the brightness of stars. She used a meterstick, a light meter, and a lightbulb. She placed the bulb at the zero end of the meterstick, then placed the light meter at the 20 cm mark and recorded the distance and the light- meter reading in her data table. readings are in luxes. luisa then measured the light intensity. luisa incread the distance from the bulb to the light meter and took more readings.
data [effects of distance on light]
distance(cm) meter reading (luxes)
20 4150.0
40 1037.5
60 461.1
80 259.4
10 ?????
what would be the light intensity for 10 cm???

2007-09-26 15:23:12 · 2 answers · asked by hmmm... 3

Bob and Bill were washing cars. Bob can wash a car in 6 minutes. Bill can wash a car in 8 minutes. How long will it take if Bob and Bill wash a car together?

It doesn't have to be this exact problem but how do you solve these type in general. Show steps please, and explain reasoning behind equations.

2007-09-26 15:21:16 · 7 answers · asked by Tesline T 2

8-3( p-4) = 2p
i got 7.3
what i did was do
8-3p-12=2p
3p-20=2p
then i added 20 to 2p and got 22
then divided it by 3p so i got 7.3 is that right??

2007-09-26 15:18:07 · 3 answers · asked by Anonymous

x+3 y-1
----- + -------= 1
4 3

2x-y= 12

im so confused on doing this problem... thanks for helping

2007-09-26 15:17:47 · 3 answers · asked by ??? 2

2007-09-26 15:13:59 · 4 answers · asked by Abiku 6

how to solve? please help

2007-09-26 15:11:39 · 9 answers · asked by anteater42001 1

2007-09-26 15:11:32 · 23 answers · asked by birmingham927 2

Okay The Questions are...

1) A car has a length of 4.97 meters. What is the length of this car in centimeters?


2) A gallon jug has a capacity of 3.785 liters. What is the capacity of the gallon jug in milliliters?

3) A piece of paper has a mass of 2.1 milligrams. What is the mass of this piece of paper in grams?

2007-09-26 15:06:03 · 5 answers · asked by Jennifer 1

f(x)=(3x^3-x^2+x-7)/(2x^3+4x-5)

I know what the answer is but I don't know how to do it. Thanks.

2007-09-26 15:05:18 · 3 answers · asked by Cham Cham 2

i got the answer n=.25 but im not sure if im wrong please show me how you got the answer

2007-09-26 14:59:38 · 2 answers · asked by Anonymous

just as the question implies.

2007-09-26 14:59:00 · 2 answers · asked by nate m 1

Mia is counting pond life animals.In two hours she counted 4 more frogs then turtles.The number of crayfish she counted was 3 more than twice the number of turtles.She counted 75 pond animals all together.How much of each did she count.


P.S. first person to give the right answers gets 10 pts.

2007-09-26 14:58:16 · 3 answers · asked by Anonymous

math question

2007-09-26 14:47:29 · 10 answers · asked by frm11dogs 1