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Noob ratio maths help

Discussion in 'General Discussion' started by Lokai, Oct 29, 2013.

  1. Lokai

    Capodecina

    Joined: Jun 26, 2008

    Posts: 16,632

    Location: Wakefield

    Looking for a little assistance with a maths questions for someone that hasn't studied in 18 years -

    Taking two figures (380 ppm carbon dioxide and 1750 ppb methane), express the ratio of co2 to ch4 in the format x: 1, where x is a whole number given to two significant figures.

    If someone could point me in the right direction it would be greatly appreciated.
     
  2. ~>Dg<~

    Caporegime

    Joined: Jun 1, 2006

    Posts: 27,154

    Location: Notts

  3. dl8860

    Wise Guy

    Joined: Jul 25, 2010

    Posts: 1,505

    Location: W9

    If you divide the larger number by the smaller number when both are in equal units, the number you get is the 'x' you are looking for.
     
  4. The Dread Pirate

    Capodecina

    Joined: Aug 15, 2007

    Posts: 15,794

    Location: Outside in the bushes

    Do Your own Damn Homework!:mad:

    :p
     
  5. rubberduck

    Mobster

    Joined: Feb 8, 2004

    Posts: 2,505

    1750 ppb = 1.75 ppm

    So 380/1.75 = 217.14

    So i guess the answer is 217.14 : 1
     
  6. Lokai

    Capodecina

    Joined: Jun 26, 2008

    Posts: 16,632

    Location: Wakefield

    Great, thanks for your help, i wasn't converting the methane to ppm from ppb which is where i was going wrong.
     
  7. Freakbro

    Sgarrista

    Joined: Jul 29, 2010

    Posts: 9,665

    Location: Lincs

    Except it asks for a whole number to 2 significant figures, not 2 decimal places - which wouldn't be a whole number anyway.

    So the answer would be 220 : 1

    But well spotted on the ppb I hadn't noticed that :p
     
  8. Rudeboy1

    Hitman

    Joined: Sep 26, 2013

    Posts: 560

    567
     
  9. Spunkey

    Capodecina

    Joined: Oct 18, 2002

    Posts: 12,651

    Location: The land of milk & beans

    Doesn't 'significant figures' mean 'integer', not nearest factor of 10? I made the answer 217:1
     
  10. Freakbro

    Sgarrista

    Joined: Jul 29, 2010

    Posts: 9,665

    Location: Lincs

    No, significant figures means just that, the first set of numbers starting with one that is not zero, then you round up as normal.

    So 655,464 to 3 significant figures would be 655,000
    to 2 significant figures would be 660,000
    and to 1 significant figure would be 700,000
     
    Last edited: Oct 29, 2013
  11. Spunkey

    Capodecina

    Joined: Oct 18, 2002

    Posts: 12,651

    Location: The land of milk & beans

    [​IMG]
     


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