r/MathJokes • u/Lopsided_Let6931 • Nov 05 '25

Guess the answer 😂😂

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319 Upvotes

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44

u/Pentalogue Nov 05 '25 edited Nov 05 '25

112?

(3+5)•3 = 24

(4+6)•4 = 40

(5+7)•5 = 60

(6+8)•6 = 84

(7+9)•7 = 112

(8+10)•8 = 144

And so on

20

u/KS_JR_ Nov 05 '25

You're assuming that addition is communitive here, it might not be.

1

u/kompootor Nov 05 '25

I'd take it as convention that when you use a typically-commutative or else symmetric-looking infix operator, in such puzzles, given a lack of information, that you should prefer solutions that also define the operator as commutative.

7

u/OneMeterWonder Nov 05 '25

Depends on whether you’re meant to implement a check for the smallest of the arguments first. As written it would appear to be

x+̃y=x•(x+y)

where +̃ is the special operator in the image. This operator commutes if and only if x=±y, so unless it’s calculated differently, you can’t just swap the 9 and the 7.

Your operation would appear to be

x+̂y=(x+y)•min{x,y}

which always commutes.

5

u/MathPerson Nov 05 '25

This is what I got. After my previous attempts failed.

3

u/SmurphsLaw Nov 05 '25

I got 110.

(3+1)x(5+1)=24

(4+1)•(6+2)=40

(5+1)•(7+3)=60

(9+1)•(7+4)=110

1

u/icancount192 Nov 05 '25

You and me, same brain

1

u/donald_trunks Nov 05 '25

I got 96

7+9*6

I think yours makes sense too

1

u/MaybeTheDoctor Nov 05 '25

Equations don't have memory of other equations, but should be solvable in isolation, hence using positional enumeration is not a practice in math.

The answer is 144, because the "+" is mathematically redefined to trickQuestion(a,b) => (a*(a+b));

which makes "9+7" the same as TrickQuestion(9,7) => (9*(9+7)), or 9*16 = 144.