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Thalia

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Posts posted by Thalia

  1. A simple Coffee Problem

    in New Logic/Math Puzzles

    Posted

    Spoiler

    14.67 oz, 90% coffee

     

    3 cups=24oz = 3 half jars +2 oz 

    24oz=1.5J+2

    J=14.67oz

     

    First fill=50% coffee

    2nd fill is half 50%, half 100% = 75% coffee

    3rd fill is half 75%, half 100% = 87.5% coffee

    Last fill is (14.67/2)x0.875+2=8.42oz coffee

    The last fill total volume is 14.67/2+2=9.34

    8.42/9.34=90%

     

  8. Make Three 7's equal 10

    in New Logic/Math Puzzles

    Posted · Edited by Thalia

    On 8/25/2021 at 3:39 PM, bonanova said:

    Using the number 0 or extra 2's does not fit the allowed operations.

    Only Sqrt(4) + 4 + 4 = 10 seems allowable.

    I don't see anything barring use of other numbers in exponents. Nothing explicitly says you can only use 7s. It's certainly implied that the 3 7s are the central parts so you can't do something like add or subtract a different number but you can square or cube.

    Closest I can get with the more limited interpretation: 7!/sqrt(7!)÷7=10.14

    Looser interpretation: (7!)^(1/5)+(7!)^(1/5)-7^0=10.003

  9. Finding a fiver

    in New Logic/Math Puzzles

    Posted

    Spoiler

    Can't come up with all the math right now but I'll take a general stab at it. There are 26 letters in the alphabet so 26^5 possible 5 letter sequences. Hopefully the word list was in a word document so you have a word count... You pick 7 letters at random. So 7!/(7-5)!=2520 sequences that may or may not be words. Then you'd determine the probability that after picking 2520 sequences out of 26^5 possibilities, you haven't formed a word. Subtract that off 1 and you have the probability of getting at least one word. 

    As for the expected number of words, divide the number of words in the list by 26^5 to get the percentage of sequences that are words. Take that percentage of 2520. I think... that class was so long ago...

     

  12. Fuel tanker

    in New Logic/Math Puzzles

    Posted

    I'm not completely sure what you're asking here. If you have to transport 50,000 L of fuel, you better have 50,000 L stored at the end of this.

    If you're asking how much you needed to have to deliver 50,000 L, you'd have to factor in the gas consumption. 

    It's going to take multiple trips as the tanker can only hold 12,500 and you lose the gas to drive between the two points. 20 L per 100 km over 2500 km. That's 500 L to go one way. Then the tanker has to go back. So you can deliver 11,500 L per run. 4 runs will get you 46,000 L (and consume 4,000 L). Last run will take 4,500 L assuming you don't plan to take the tanker anywhere after that. I come up with 54,500 L.

  23. Who's keeping score?

    in New Logic/Math Puzzles

    Posted

    Spoiler

    Assuming "X beat Y and Z" allows X to beat Y but lose to Z.

    Ed, Jim, Bill, Tom

    Ed:
    Bill wasn't last.
    I was the winner.
    Jim finally broke 100.
    I shot 98.

    Jim:
    I beat Bill     and Ed.
    The last hole was not my best.
    We didn't all break 100.
    Tom wasn't the winner.

    Bill:
    I beat Jim and Tom.
    Ed shot 111.
    Jim took 6 on the last hole.
    None of us broke 100.

    Tom:
    Ed beat Bill.
    I was the winner.
    Bill placed between Ed and Jim.
    The last hole was Jim's best.

     

  24. Who's keeping score?

    in New Logic/Math Puzzles

    Posted · Edited by Thalia

    Spoiler

    Ed:
    Bill wasn't last.
    I was the winner.
    Jim finally broke 100.
    I shot 98.

    Bill:
    I beat Jim and Tom.
    Ed shot 111.
    Jim took 6 on the last hole.
    None of us broke 100.

    Tom:
    Ed beat Bill.
    I was the winner.
    Bill placed between Ed and Jim.
    The last hole was Jim's best.

    Jim:
    I beat Bill and Ed.
    The last hole was not my best.
    We didn't all break 100.
    Tom wasn't the winner.

    With the previous assumption about the meaning of between.

  25. Alphabet baseball

    in New Logic/Math Puzzles

    Posted

    17 hours ago, bonanova said:

    Initials occurring in odd positions of the alphabet must have held even positions in the circle. 

    That doesn't give any information about the team. The order could be Taylor, Miller,  Brown, Gerson Jenkins, Adams, Babcock, Carver, Randolph, Smith, Flynn, Sawyer, Timmons, Myers, Lucas, Morton, Peters, Young. The first 9 could be Cons and they still wouldn't call their initials. 

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