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Math Riddle

Jc -  
Pierr10 Posted messages 13848 Registration date   Status Moderator Last intervention   -
Je suis 8495.

5 answers

  1.
    jordane45 Posted messages 30427 Registration date   Status Moderator Last intervention   4 832
     
    Hello,
    9995

    --
    .
    Best regards,
    Jordane
    2
    1. Jc
       
      Thank you, I will be able to explain it to my son. Have a good day.
      0
  2. baladur13 Posted messages 47369 Registration date   Status Moderator Last intervention   14 403
     
    Hello
    sum 32
    32 - 5 = 27
    Now to find three numbers whose sum is 27
    only solution 9
    9995

    --
    Very difficult to catch a black cat in a dark room.
    Especially when it's not there...
    1
  3. T3chN0g3n Posted messages 69 Registration date   Status Member Last intervention   1 217
     
    Hello,

    it would be too easy to give the answer directly =D, start from the constraint of "5", it is imposed so you must subtract it from 32 from the beginning to get the "available" sum for the remaining numbers, then you just need to see how this remainder is divisible to meet the other constraints...

    Best regards.
    0
  4. Pierr10 Posted messages 13848 Registration date   Status Moderator Last intervention   5 850
     
    Hello

    I'm arriving after the battle. Nevertheless, I'm providing the detailed solution:

    We start by noticing that a 3-digit number is not compatible with the condition "sum of the digits = 32"
    (the largest 3-digit number would be 995, whose digit sum is 23)

    The sought number is therefore of the form abb5 (it must be less than 10000).
    So a + 2b + 5 = 32
    and a + 2b = 27

    2b is an even number; a must therefore be odd.
    We proceed by elimination in search of possible values for a
    The values 1, 3, 5, 7 are not suitable because they give a 2-digit number for b.

    Thus, the remaining value is 9 for a
    9 + 2b = 27
    2b = 18 and b= 9

    The sought number is therefore 9995

    What is well understood is clearly expressed,
    And the words to say it come easily.
    (Boileau)
    0
  6. T3chN0g3n Posted messages 69 Registration date   Status Member Last intervention   1 217
     
    Not even funny, you need to let it think a little =D
    0
    1. Pierr10 Posted messages 13848 Registration date   Status Moderator Last intervention   5 850
       
      It's true!

      I gave the details because of the response <3>.
      As much as the explanations given to the kid should be the right ones!
      0