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Thread: Go Figure (mind game)

  1. #811
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    Quote Originally Posted by venuspop
    Two identical tanks full of water are being drained at the same time. One of the tanks has one - two centimeter circular drain outlet and the other has two - one centimeter circular drain outlets. Will one of the tanks empty faster than the other? Please give reasons for your answer.[/i]
    If circular means circumference of tap, then the tank with two one cm circular drain outlets will drain faster - 2 times faster than the one with a one two cm circular drain outlet.

    r = Small pipe radius = 1/2pi
    R = Big pipe radius = 1/pi

    Area of small pipe = 1/4pi
    Area of big pipe = 1/pi

    2 times area of small pipe = 1/2pi

    Hence 1 big pipe flows 2 times faster than 2 small pipes since time and height of pipe is constant.
    -"Things do not happen...things are made to happen"-John F.Kennedy

  2. #812
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    Quote Originally Posted by Jeyanthy
    If circular means circumference of tap, then the tank with two one cm circular drain outlets will drain faster - 2 times faster than the one with a one two cm circular drain outlet.


    Hence 1 big pipe flows 2 times faster than 2 small pipes since time and height of pipe is constant.
    Sister, you are contradicting yourself. Can you explain your workings again please. 1/pi? Your area, I think is incorrect. Does / mean divide?

  3. #813
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    Quote Originally Posted by venuspop
    Yes, Peter, you've got the correct formula. Just want to clarify. You mentioned that the rate depends on the radius and therefore concludes that the 2 cm single outlet empties faster.

    Are you saying that the other tank with contains TWO one cm circular drain outlets empties slower or did you miss that out?
    Tank with 1 two-cm diameter will drain faster..
    Tank with 2 one-cm circular holes will drain slower..

  4. #814
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    Since Jeyanthy came out with the formula, Peter, we'll keep this simple.

    What's the area of the one big drain and the aggregate area of the two small drains?

  5. #815
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    Quote Originally Posted by venuspop
    Sister, you are contradicting yourself. Can you explain your workings again please. 1/pi? Your area, I think is incorrect. Does / mean divide?
    Aduh sorryla. Susah nak taip. Easier to write formula and write conclusion.

    Ok here goes:
    If circular means circumference of tap, then 1 big pipe flows 2 times faster than 2 small pipes since time and height of pipe is constant.

    r = Small pipe radius = 1/2pi
    R = Big pipe radius = 1/pi

    Area of small pipe = 1/4pi
    Area of big pipe = 1/pi

    2 times area of small pipe = 1/2pi
    -"Things do not happen...things are made to happen"-John F.Kennedy

  6. #816
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    Quote Originally Posted by venuspop
    Since Jeyanthy came out with the formula, Peter, we'll keep this simple.

    What's the area of the one big drain and the aggregate area of the two small drains?
    It's only a game Venus...p

    next question/riddle please..

  7. #817
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    Quote Originally Posted by Jeyanthy
    Aduh sorryla. Susah nak taip. Easier to write formula and write conclusion.

    Ok here goes:
    If circular means circumference of tap, then 1 big pipe flows 2 times faster than 2 small pipes since time and height of pipe is constant.

    r = Small pipe radius = 1/2pi
    R = Big pipe radius = 1/pi

    Area of small pipe = 1/4pi
    Area of big pipe = 1/pi

    2 times area of small pipe = 1/2pi
    Jeyanthy, your workings and mine differed so let's walk through the answer. We'll start with the big pipe. Your area is 1/pi (1 divided by 3.14 = 0.32)
    My area is just pi (3.14)
    Looks like my area is significantly bigger than yours. Typo error perhaps?

  8. #818
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    Quote Originally Posted by venuspop
    Jeyanthy, your workings and mine differed so let's walk through the answer. We'll start with the big pipe. Your area is 1/pi (1 divided by 3.14 = 0.32)
    My area is just pi (3.14)
    Looks like my area is significantly bigger than yours. Typo error perhaps?
    Let R = big pipe radius
    2 x pi x R = circumference
    2 x pi x R = 2cm
    R = 1 / pi ==> / means divide
    -"Things do not happen...things are made to happen"-John F.Kennedy

  9. #819
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    Quote Originally Posted by PeterHng
    Tank with 1 two-cm diameter will drain faster..
    Tank with 2 one-cm circular holes will drain slower..
    Quote Originally Posted by Jeyanthy
    Let R = big pipe radius
    2 x pi x R = circumference
    2 x pi x R = 2cm
    R = 1 / pi ==> / means divide
    Now I geddit. I must have missed this in your first post. No wonder the workings do not agree. A 2 cm circular drain would usually mean that the diameter is 2 cm and not the circumference. But since your choice is the right one, you are correct just as Peter is also correct. So, for the record....

    B i n g o !!

  10. #820
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    New Riddle:

    Three men sitting in a small motorboat one mile from the shoreline. The first is afraid of water, the second afraid of drowning, and the third afraid of sharks. The boats motor is not operational and there is nothing to row with. How do they get to the shoreline.
    -"Things do not happen...things are made to happen"-John F.Kennedy

  11. #821
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    I think I've heard this one before. Will let someone else try.

  12. #822
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    The Kid would like to give a creative answer to this.

    The one who is afraid of water - stay in the boat, steer and watch out for sharks.
    The one who is afraid of drowning - hold on to the boat as he kicks hard in the water, pushing the boat.
    The one who is afraid of sharks - do the same.

    How's that ?

  13. #823
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    Quote Originally Posted by akiyoshi
    The Kid would like to give a creative answer to this.

    The one who is afraid of water - stay in the boat, steer and watch out for sharks.
    The one who is afraid of drowning - hold on to the boat as he kicks hard in the water, pushing the boat.
    The one who is afraid of sharks - do the same.

    How's that ?
    Sorry, give it another go.....
    -"Things do not happen...things are made to happen"-John F.Kennedy

  14. #824
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    Quote Originally Posted by Jeyanthy
    New Riddle:

    Three men sitting in a small motorboat one mile from the shoreline.
    This can be either side. Since it didn't specifically mention that they are one mile from the shoreline in the water. I would say they are sitting on the small motorboat onshore. So, they need to get out of the boat and walk to the shoreline?
    Every Birth Begins With Labour Pains

  15. #825
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    Quote Originally Posted by birdy
    This can be either side. Since it didn't specifically mention that they are one mile from the shoreline in the water. I would say they are sitting on the small motorboat onshore. So, they need to get out of the boat and walk to the shoreline?
    Welcome back Birdy and the answer is

    "C O R R E C T!!!"
    -"Things do not happen...things are made to happen"-John F.Kennedy

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