Tester Quiz


A short post today because I am pushing all the work over to you! <g/> How many answers to “38.30 – 1 1/2 = ???” can you think of? Here are a few to get you started:

  • 36.80 (assuming both are decimal numbers)
  • 36.30 (assuming minutes.seconds)
  • An error message that “38.30” is an invalid number in the current locale (assuming the current locale treats the period as a thousands separators rather than a decimal point)

Post your answers in the comments!

Comments (18)

  1. Matt says:

    So, this one is a little far out but say we  collapses all spaces in a math equation.. the answer then would be 32.8 (39.30-5.5)

    or, say order of operations is addition/substraction before mult/div and the spaces are dropped… we get 13.65 via (38.30-11)/2

  2. Erling Paulsen says:

    *A parser error, some locales don’t use the period mark at all(for instance, scandinavian languages)

    *36 – assuming int as datatype, C# as language

    *37 – assuming int as datatype, vb.net as language(vb.net uses bankers rounding, totally messed up)

    Hmmm… maybe not enough coffee yet.  Can’t think of any more…

  3. Scott says:

    33.30 (assuming whitespace is ignored and ‘1 1/2’ evaluates to an integer)

    32.80 (assuming whitespace is ignored and ‘1 1/2’ evaluates to a decimal)

    37.30 (assuming ‘1/2’ evaluates to an integer)

  4. 38.30-1 1/2

    Hi Michael,

    I was think on post at night but.. I presume that Michael Bolton or James Bach where about to post here with: "What is the context?" and thats right, there are multiple answers and one valid for the context .. 😉

    one of the multiples ones is to assume that the dot is in the context a multiplication operator so:

    38.30 – 1 1/2 = 1140 – 1 1/2 = 1138 1/2 (aka. 38×30 – 1.5 = 1140 – 1.5 = 1138.5)

    Another thing is to presume that the calculator or the input innores the space character so it translate as: 38.30 – 11/2 and then the answer is 32.8

    and so on…

  5. larmccoy says:

    Wouldn’t 38:30 be 38 minutes 30 seconds, which is 38.5 minutes?  If you subsection 1 1/2 minutes, the result would be 37 minutes, right?

  6. micahel says:

    larmccoy: You’re right, my math was completely wrong on that one!

  7. Valentin Iliescu says:

    * parser error: 1 1/2 is not valid in many programming languages

    * degree-minute-second format

    38.3 – 1 1/2 = 37 degrees

  8. Apoorva says:

    Apart from all of the above – my take:

    38.30 – 1 1/2 = 38.30 – 1 1/2

    Completely depends what and where I am working on! I work on a software called SAS, where they have a feature called macro variables. If you assign a macro variable to 38.30 – 1 1/2, it treats everything as text and the final result is going to be exactly what you pass to it.

  9. Pierzapin says:

    No one has said what base we’re working in. Sure you can assume base10 and the equation itself implies at least 8 digits – but infinite possibilities still remain.

  10. Li says:

    Try to input 38.30 – 1 1/2 into IE address bar.

  11. Shrini says:

    MS Word Zoom percentage gives “This is not a valid measurement”

    Excel gave 36.8 while it converted 11/2 as 1.5

    Google gave it 36.8 while it interpreted 38.30 – (1 1/2) = 36.8

    MSN gave 32.8 considering 11/2 as 5.5

    Yahoo search engine treats it as a string input and gives the results like “Filson Bridle Belt 1 1/2" 30-38"”

    Basic Calculator at http://www.math.com does not recognize it as a valid arithmetic expression

    Space between 1 and 1/2 makes a difference in Excel again. One space would give 36.8 while more than one space would give a formula error proposes a correction as 11/2

    38.30-1 ½ – this fraction character when copied to excel gives formula error

  12. I.M.Testy says:

    Michael, this is a trick question…right?

    I wouldn’t even begin to waste my time trying to come up with answers to this problem, because they would simply be wild-ass guesses.

    But, I could come up with a lot of questions! 🙂

    If I asked this question in an interview, and the person being interviewed just started throwing out wild-ass guesses without asking some very smart precision questions to better define the problem space I frankly wouldn’t be very impressed. But, that is my opinion.

  13. Bhargavi says:

    my take in different contexts:

    * 37.00(assuming hours.minutes)

    * 36.8(assuming only the last one digit after decimal is considered)

    * 36.8(assuming white space after decimal is considered as zero)

    * 736/20 or 184/5 (answer in terms of fraction)

    * 36 4/5 or 18 4/10 or 9 4/20 or 3 4/60 or 1 4/180(answer interms of mixed fraction)

  14. Bhargavi says:

    Hi

    Likewise I can  think of few more answers

    3680*(10^-2) or 368.0*(10^-1) or 3.680*(10) or 0.3680*(10^2) and so on..depending on the context.

  15. micahel says:

    Testy et al:  Yes this is a trick question. And it isn’t. In a "’test this" situation, I would indeed expect a bunch of questions about context, as you and Alejandro suggest. In a brainstorming situation, however, I generally leave the discussion wide open, as too many constraints can eliminate ideas before they ever thought. (And yes, even then there is *some* context.)

    Thanks for calling me out! I will be more precise next time.

  16. My Answers:

    * 18.65 ( assuming 38.30 -1 = 37.30 and then 37.30 * .5 = 18.65)

    * 37.00(assuming hours and minutes)

    * 36.80 (assuming both are decimal numbers)

    * 33.30 ( assuming  1 1/2 is treated as 11/2 which is truncated to 5)

    * 37 29.5 (assuming Kms and mts…First would turn out to be 38 Km 30 mts and second one will be 1 Km and .50 mts)

    * 32.80 (assuming space is ignored and ‘1 1/2’ evaluates to a decimal)

  17. Neelam says:

    36.8 – If both are decimal

    Feb 5, 1990 7:12pm – if both are days

        (38.30 – 31 = 7.30; i.e. 7Feb .30 day

         7.30 – 1.5 = 5.8; i.e. 5 Feb .8 day

         i.e. 5 feb .8*24 = 5 feb 19.2 hrs

         i.e. 5 feb 19hrs .2*60 mins

         i.e. 5 feb 19 hrs 12 mins)

    36 4/5 – if its a fraction calculation

    3.68E+01 – if its a scientific calculation

  18. Travis says:

    If the calculator is Reverse Polish Notation (http://en.wikipedia.org/wiki/Reverse_Polish_notation)

    Then the entries are

    38

    – (at this point the result is -38)

    1 1

    /

    2

    When you get to ‘1 1’ an error is given that its not a number.

    If that error is ignored by the calculator or a script in the case of automating the operations ; the calculation will become

    38

    /

    2

    Which assuming all stack values are zero to start with becomes

    0

    38

    / (at this point the result is 0 => (0 / (0 -38))

    2

    Which gives the answer of 2 because the 2 entered at the end.