Yullock

Saturday, October 30, 2004

A Call Day Puzzler

Long call today. This is the first year I have not celebrated gaining an extra hour in switching back to standard time. But, this GI subI is nice because I'm on a q6 call schedule: long call (taking admissions only from noon to midnight), post call, short call (admissions 7 am to noon), regular day, short call, regular day.

So here is the puzzle my senior resident posed to us on rounds today: a man walks into a 7-11 and purchases four items. The total came out to $7.11, but the clerk had accidentally rang it up by multiplying the cost of all four items. However, when the clerk re-rang the total by adding all four items, the total still came out to be $7.11. What was the cost of each of the four items? Anyone, anyone?

EY

6 Comments:

  • At November 1, 2004 at 9:23 PM, Anonymous Anonymous said…

    this problem is not do-able unless there's more info or some trick im missing:

    1) u can only make up two equations and you have to solve for four unknowns (need more eqns):
    wxyz = 7.11
    w+x+y+z = 7.11

    2)its too hard to guess and check cause prices of things dont always come out to be whole numbers.

    3) if w=x=y=z it would easier but there is no solution then:
    w^4 = 7.11 ---> w = 1.63
    and
    4*w = 7.11 ---> w = 1.78
    The w's dont match so no solution.

    ***if you find out the answer... i would love to know!

    ~pings

     
  • At November 1, 2004 at 10:05 PM, Anonymous Anonymous said…

    http://home.att.net/~numericana/answer/recreational.htm#7-11

    answer:
    7.11 = 3.16 + 1.25 + 1.50 + 1.20
    = 3.16 x 1.25 x 1.50 x 1.20

    ~pings

     
  • At November 1, 2004 at 10:05 PM, Anonymous Anonymous said…

    http://home.att.net/~numericana/answer/recreational.htm#7-11

    answer:
    7.11 = 3.16 + 1.25 + 1.50 + 1.20
    = 3.16 x 1.25 x 1.50 x 1.20

     
  • At November 3, 2004 at 7:31 PM, Blogger Yullocks said…

    I took one year's worth of engineering level calculus in undergrad, so I'm not a complete math idiot, but I got lost in the first sentence of this 27 sentence proof! What the *#@?!??? Pings, can you translate it to English plz???

     
  • At November 12, 2004 at 4:50 AM, Anonymous Anonymous said…

    sigh, i can't believe math is so unentertaining by itself that a person wanting to play with it has to make up his own game and then see what happens. is this not the case or is there some theoretical basis that made this problem possible. that's rhetorical

     
  • At November 12, 2004 at 4:55 AM, Anonymous Anonymous said…

    hm it's not theory after all! it's integration of simple facts that we should all 'know'...

    this explanation required less thinking, thank goodness

    http://jwilson.coe.uga.edu/emt725/Class/Lanier/Seven/Seven.html

     

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