3 digit PIN The SECOND and THIRD digits make a 2-digit number The FIRST number is a FACTOR of the 2-digit number Th

Question

3 digit PIN
The SECOND and THIRD digits make a 2-digit number
The FIRST number is a FACTOR of the 2-digit number
The SUM of the 3 digits is 13
The three digit number is a square number

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Orla Orla 6 months 2021-07-18T11:14:54+00:00 1 Answers 7 views 0

Answers ( )

    0
    2021-07-18T11:16:34+00:00

    let’s start with the last to clues and make a list of all 3-digit square numbers (and by making I mean just looking it up. it would be possible, but it’s faster and lazier)

    100

    121

    144

    169

    196

    225

    256

    289

    324

    361

    400

    441

    484

    529

    576

    625

    676

    729

    784

    841

    900

    961

    (source: https://math.tools/table/square-numbers-list

    but I had to copy by hand…)

    now let’s eliminate all numbers from the list that don’t have 13 as the sum of their digits and just keep the few that will remain.

    256

    625

    841

    now that’s pretty much narrowing it down already, now let’s test for the first two clues (I would have no idea how to start with these so I switched the order to make it doable)

    The SECOND and THIRD digits make a 2-digit number

    The FIRST number is a FACTOR of the 2-digit number

    only 256 works, 2 is a factor of 6, but that wouldn’t word for the other candidates. so 256 is the number we are looking for.

    summing up the second and the third digit (I guess summing up the digits was meant here) also works for 256, if we wanna see a two-digit number as a result.

    the key part here was to ignore the order the clues where listed I guess. much easier with just 3 possible numbers.

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