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aniked [119]
3 years ago
15

One pump can fill a reservoir in 60 hours. Another pump can fill the same reservoir in 80 hours. a third can empty the reservoir

in 90 hours. If all three pumps are operating at the same time, how long will it take to fill the reservoir?
Mathematics
2 answers:
steposvetlana [31]3 years ago
7 0

one pump, let's call it A, fills the reservoir by 1/60 every hour. Now, B fills it by 1/80 every hour. C empties it by 1/90 every hour. All three are on, so now we combine them into one function: t(1/60 + 1/80 - 1/90) = 1, where t = the time it takes to fill it, and 1 is just our "reservoir finally filled" marker.

isolate t onto one side and we see t = 720/13 exactly, or approximately 55.38 hours. let me know if this is the wrong answer but I'm pretty sure it is correct!

11111nata11111 [884]3 years ago
4 0

Answer:

1/time needed = 1/time of 1st pump + 1/time of 2nd pump - 1/time of 3rd pump

1/t = 1/t1 + 1/t2 - 1/t3

1/t = 1/60 + 1/80 - 1/90

1/t = 12/720 + 9/720 - 8/720

1/t = 13/720

t = 720/13 hours = 55.38 hours = 55 hours 23 minutes

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Answer:

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Step-by-step explanation:

area of triangle = length * height * 1/2

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6 0
3 years ago
The vertex of a parabola is (0,0)and the focus is (1/8, 0) . What is the equation of the parabola?
Aleonysh [2.5K]

The equation of a parabola whose vertex is (0, 0) and focus is (1 / 8, 0) is equal to x = 2 · y².

<h3>How to derive the equation of the parabola from the locations of the vertex and focus</h3>

Herein we have the case of a parabola whose axis of symmetry is parallel to the x-axis. The <em>standard</em> form of the equation of this parabola is shown below:

(x - h) = [1 / (4 · p)] · (y - k)²     (1)

Where:

  • (h, k) - Coordinates of the vertex.
  • p - Distance from the vertex to the focus.

The distance from the vertex to the focus is 1 / 8. If we know that the location of the vertex is (0, 0), then the <em>standard</em> form of the equation of the parabola is:

x = 2 · y²     (1)

The equation of a parabola whose vertex is (0, 0) and focus is (1 / 8, 0) is equal to x = 2 · y².

To learn more on parabolae: brainly.com/question/4074088

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5 0
2 years ago
HEEEEEEEEEEEEEEEEEEEEEEEEELP!
Law Incorporation [45]
Hey there Rosy! I did this recently and the answer is:

1 : 4

2 to 8

18
---
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7 0
3 years ago
Use gcf distributive property to find the sum of 28 and 80.
Anna71 [15]

Step-by-step explanation:

The GCF of 28 and 80 is 4.

<u>Distribute 4 for 28 and 80, then solve:</u>

4(7) + 4(20) = 28 + 80

4(7 + 20) = 28 + 80

4(27) = 28 + 80

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What is 5/20 as a percent if you could give an explanation that would be good but if not thats okay
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5/20 can also be represented as 25/100 or 25%. The can be done by multiplying the top and bottom both by 5 and then dividing our numerator (25) by our denominator(100) to get the %.
3 0
3 years ago
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