Solve this math puzzle

[Augie]

interesting I did it as ((a+b) x a) - a = c

Interesting...I copied off the guy to my left.

[/dev/null]

3.5

[Marv's Neighbor]

2+3=8

3+7=27

4+5=32

5+8=60

6+7=72

7+8=?

 

Bite me!!

[Augie]

Bite me!!

Now, now....use your words!

[Doc]

Again, 15. Since when and why did "+" become "make up some weird equation to create math puzzles"?

[Augie]

Again, 15. Since when and why did "+" become "make up some weird equation to create math puzzles"?

I think you could get a meadcoin, you should be respectful!

[Doc]

I think you could get a meadcoin, you should be respectful!

 

...why?

[Augie]

...why?

I'm told they will become worth..........something? Possibly a fraction of a Stromboli!

 

(I've already done enough math, so that's out.)

[mead107]

Get enough meadcoins and you can get a whole Stromboli.

[Augie]

Get enough meadcoins and you can get a whole Stromboli.

I'm concerned about how many digits and comas are involved. Is this yen or pesos, or Berkshire Hathaway stock?

Edited October 16, 2017 by Augie

[Doc]

7meadcoin+8meadcoins=?

[Augie]

7meadcoin+8meadcoins=?

3.5?

 

Maybe 98....I don't know.

[SinceThe70s]

a+b=c

(a+b-1) x a = c

 

if a = 7 and b = 8, c=98.

 

FWIW, I looked at it using a sequence:

 

1. 2+3=8

2. 3+7=27

3. 4+5=32

4. 5+8=60

5. 6+7=72

6. 7+8=?

Using the sequence number, this equation works:

a*b + seq*a = c

7*8 +6*7 = 98

[DC Tom]

 

FWIW, I looked at it using a sequence:

 

1. 2+3=8

2. 3+7=27

3. 4+5=32

4. 5+8=60

5. 6+7=72

6. 7+8=?

Using the sequence number, this equation works:

a*b + seq*a = c

7*8 +6*7 = 98

 

Same equation. In each case, seq = a - 1. So a*b + seq*a = a*b + (a-1)*a = (a+b-1)*a.

[SinceThe70s]

 

Same equation. In each case, seq = a - 1. So a*b + seq*a = a*b + (a-1)*a = (a+b-1)*a.

 

I was assuming the order of the equations mattered and was independent of a:

 

3+7 = 3*7 + 3*1 = 24

2+3 = 2*3 + 2*2 = 10

[DC Tom]

 

I was assuming the order of the equations mattered and was independent of a:

 

3+7 = 3*7 + 3*1 = 24

2+3 = 2*3 + 2*2 = 10

 

Well, I just disproved your assumption, didn't I?

[SinceThe70s]

 

Well, I just disproved your assumption, didn't I?

 

...or there's more than one possible solution.

 

If we can assume a '+" somehow relates to a*b + (a-1)*a no reason we couldn''t also assume the sequence of the equations has significance.

 

In truth, I like the a*b + (a-1)*a solution better, just thought it was interesting that I came at it from a slightly different angle.

[DC Tom]

 

...or there's more than one possible solution.

 

If we can assume a '+" somehow relates to a*b + (a-1)*a no reason we couldn''t also assume the sequence of the equations has significance.

 

In truth, I like the a*b + (a-1)*a solution better, just thought it was interesting that I came at it from a slightly different angle.

 

Except I already demonstrated that, if sequence is important, it reduces to the previous solution.

 

Or, to put it a different way: if you create a solution for a specific case (where a specific sequence matters), and that solution can be generalized (to a solution that's sequence-independent), the general solution is considered the correct one.

[SinceThe70s]

 

Except I already demonstrated that, if sequence is important, it reduces to the previous solution.

 

Or, to put it a different way: if you create a solution for a specific case (where a specific sequence matters), and that solution can be generalized (to a solution that's sequence-independent), the general solution is considered the correct one.

.

..or if your sample set is too limited you could arrive at the wrong solution for all the right reasons.

[DC Tom]

.

..or if your sample set is too limited you could arrive at the wrong solution for all the right reasons.

 

Which is why the general case is preferred to the specific case.