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Homework Help: Astronomy Olympiad Estimation Question

  1. Jan 24, 2008 #1
    1. The problem statement, all variables and given/known data

    Q. Given that the population of Mumbai is about 13,000,000. Estimate the amount of tea that would be consumed by the city in a day?

    2. The attempt at a solution

    Now at first place I could not understand why such kind of a question is given in Astronomy Olympiad. May be they wanted to check our ability to do approximate estimation because in Astronomy and Astrophysics we have to estimate many different variables. For example, given the mass of a galaxy and average mass of a star estimate the number of stars in a galaxy.

    Regarding the above question my calculation showed nothing elegant but the necessity of 'percentage' as a mathematical tool. I don't know what did they expect.

    I saw chapters on estimation in books on statistics. Should I have included some statistical interpretation. And if so then how?

    I am expecting a question on estimation this year too. Therefore can somebody provide me with such questions and the approach of the solution so that I can have a good practice before the exam.
  2. jcsd
  3. Jan 24, 2008 #2


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    Come up with a set of factors that, when multiplied together, give the desired value. Next, estimate the value of each factor.

    For example... each resident of Mumbai drinks x cups of tea per day. Each cup of tea requires y grams of tea.

    - Warren
  4. Jan 24, 2008 #3
    Yes! I considered them. A cup of tea on an average requires 2 grams of tea leaves. An average adult drinks a cup of tea twice a day. Considering Mumbai a metropolitian city about 75% would be involved in some kind of work. About 60% of them being in working class would consume more tea-say four times a day. Considering childern and old people who do not drink tea at all and other all other factors, the problem reduces to nothing more than percentages and multiplications.

    But is it all that the problem requires? Can't it have a more formal solution that includes statistical interpretation.
    Last edited: Jan 24, 2008
  5. Jan 24, 2008 #4


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    I think you have the right idea. As long as your factors (and the values you assume for them) make sense, you should get a sensible answer.

    - Warren
  6. Jan 24, 2008 #5


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    These are very good questions for showing that someone can think, I use them a lot when interviewing engineers or programmers.

    What's the flow rate of the missippi?
    how many molecules of Ceasers last breath are in each breath you take?
    what percentage of the world's water is in a single cow?

    The classic is how many piano tuners are there in chicago.
  7. Feb 2, 2008 #6
    Today was my Astronomy Olympiad Exam. As I had expected, an estimation question came this time also. The question was 'if somebody draws a straight line with a typical ball point pen then estimate how long would that line be'. After a few estimations my answer came to be about ~2km. Now I have no idea of that figure. I just wanted to know the views of other people about my estimation.
  8. Feb 2, 2008 #7


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    Well, I don't know about you but I have never drawn a line 2 km long! Were you interpreting the question to mean "draw a straight line until the ball point pen runs out of ink"? I can see how it could be interpreted that way but it's not the way I would interpret it.
  9. Feb 3, 2008 #8
    No body draws a 2km long line(except someone who wants to get his name enlisted in Guinness World Records). The question clearly mentioned to estimate the length of a line that could be drawn until the ball point pen runs out of ink. What else could one interpet out of it.
  10. Feb 6, 2008 #9
    2km sounds quite reasonable. In fact, I just checked and bicworld puts it at between 2 and 3 km.

    http://www.bicworld.com/inter_us/stationery/faq/index.asp [Broken]
    Last edited by a moderator: May 3, 2017
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