Mathematics (Science & Mathematics) - 17 July 2007

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3 pipes A,B,C together can fill tank in 4hrs. After 1hr, C is turned off and tank is filled in 6 more hrs..?

Find time in which C alone can fill the empty tank.

My Try:
upto 1hr, 1/4th of total work is done by 3pipes together. Then 3/4th of remaining work is done by A,B. So, 1/4(efficiency of ABC)+3/4(Eff. of AB)=1
So, 1/4(1/4)+3/4(1/8)=1 => 5/32=1...eh?

Where am i wrong? Tell me the related concept..

2007-07-17 02:50:02 · 6 answers · asked by ʞzɹәႨnɹ 2

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Distance Calculus Question - Velocity and Derivatives, Parametric?

please view second problem @ http://www.market2people.com/ec1.pdf

I cant figure this out. Thanks in advance for your help.

2007-07-17 02:49:28 · 1 answers · asked by Lanksta 1

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if the ratio of a to b is 3:4 and the ratio of c to b is 9 to 10, then what is the ratio of a to c?

how do you solve this?
i never learned how....

2007-07-17 02:39:53 · 6 answers · asked by Anonymous

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are there any shortcuts in answering probability questions?

2007-07-17 02:34:17 · 2 answers · asked by Anonymous

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Why when you divide a number say 5 by 0.78 to get 22% of 5 it is a different answer to 5 * 1.22 also 22%?

2007-07-17 02:18:56 · 10 answers · asked by Anonymous

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How do i find the Maclaurin series?

Use a known result (from the power series table) to find the Maclaurin series for f(x) = e^(3x).

2007-07-17 02:09:25 · 1 answers · asked by Anonymous

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Calculus series help.?

Determine whether or not the series converges or diverges. Any test is accepted.

∑ (infinity on top; n=1 on bottom) times (3n^3/2n+1)^n.....the total problem is raised to the "n" power.

2007-07-17 01:23:32 · 1 answers · asked by Kayla G 1

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help !!!! what is the The arithmetic mean of?

81 , 52 , and 49 ! help i am rubish at maths
thank uuuuuuuuuuuuuuuuuu !

2007-07-17 01:18:03 · 4 answers · asked by Anonymous

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1. Find the median 16, 19, 17, 35,43,28,21?

2. Find the mean and median for the following data set: 1,3,8,10,18

3.One number is less than another. If 4 times the smaller number minus 3 times the larger number is 4, find the two numbers.

4. Determine the LCM of 25 and 50

5. Simplify 5- a/b is over top of 15/b

6. Is the number in the parentheses a solution to the given equation? 5 - x = 6 (-3)

2007-07-17 01:17:07 · 6 answers · asked by Anonymous

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Calculus word problem help?

The impedance Z in Ohms in an electric circuit is given by
Z=Squareroot[ R^2+(X-Y)^2 ]. If R=2500 Ohms and X=1500 Ohms, what value of Y makes the impedance a minimum?

2007-07-17 01:13:35 · 2 answers · asked by t b 1

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how to prove the closure of a set is closed??

2007-07-17 00:57:22 · 2 answers · asked by Anime Lover 3

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Find all the vertical asymptotes of the rational function F(x)=4x²-8/3x²-48?

Does f(x) have a horizontal asymptote? If so what is it?

2007-07-17 00:40:00 · 1 answers · asked by rodica 1

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What is the product of 3 consecutive integers if the largest integer is (x+1)?

Its hard.

2007-07-17 00:19:40 · 9 answers · asked by Miguel Lorenzo A 2

Mathematics - 17 July 2007