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

1. ## 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
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2. Originally Posted by KiddoNeddingHelp
[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
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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=???

3. Originally Posted by KiddoNeddingHelp
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?