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Thread: I don't know what type of maths this is but plz help

  1. #1

    Question I don't know what type of maths this is but plz help

    [COLOR=rgba(255, 255, 255, 0.7)]3+8=30 5+11=75 7+13=133 9+17=225 13+25=???


    its driving me nuts trying to figure this out for a quiz
    [/COLOR]

  2. #2
    Elite Member
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    Quote Originally Posted by KiddoNeddingHelp View Post
    [COLOR=rgba(255, 255, 255, 0.7)]3+8=30 5+11=75 7+13=133 9+17=225 13+25=???


    its driving me nuts trying to figure this out for a quiz
    [/COLOR]
    Is it a regular math-class quiz?

    Does your problem look as follows:

    If:

    3+8=30 and

    5+11=75
    and

    7+13=133 and

    9+17=225 then

    13+25=???
    “... mathematics is only the art of saying the same thing in different words” - B. Russell

  3. #3
    Elite Member stapel's Avatar
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    15,521

    Cool

    Quote Originally Posted by KiddoNeddingHelp View Post
    3 + 8 = 30
    5 + 11 = 75
    7 + 13 = 133
    9 + 17 = 225
    13 + 25 = ___

    [I]t[']s driving me nuts trying to figure this out for a quiz.
    Okay. What have you tried so far? What patterns, if any, have you detected? What method(s), if any, have you tried to apply?

    For instance, we can see the following:

    . . . . .8 = 3 + 5

    . . . . .11 = 5 + 6

    . . . . .13 = 7 + 6

    . . . . .17 = 9 + 8

    So we don't seem to have any useful patterns there. We can see the following:

    . . . . .30 = 3*10

    . . . . .75 = 5*15

    . . . . .133 = 7*19

    . . . . .225 = 9*25

    Then we can note that:

    . . . . .10 = 8 + 2

    . . . . .15 = 11 + 4

    . . . . .19 = 13 + 6

    . . . . .25 = 17 + 8

    Then we see that:

    . . . . .2 = 2*1

    . . . . .4 = 2*2

    . . . . .6 = 2*3

    . . . . .8 = 2*4

    Do these investigations lead anywhere useful?

    Please reply showing all of your work, including your consideration of the above. Thank you!

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