Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

Pages: **1**

**bhavik.shah****Member**- Registered: 2010-08-05
- Posts: 4

now lets see what you have brains or not

5+3+2=151012

9+2+4=183662

8+6+3=482466

5+4+5=202504

then

7+2+5=?????

it's a challenge... prove it.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,688

Hi bhavik.shah;

Welcome to the forum!

**In mathematics, you don't understand things. You just get used to them.Of course that result can be rigorously obtained, but who cares?Combinatorics is Algebra and Algebra is Combinatorics.**

**Online**

**John E. Franklin****Member**- Registered: 2005-08-29
- Posts: 3,562

Hi!! Welcome!! I think bobby got it right.

**igloo** **myrtilles** **fourmis**

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,688

Hi;

Maybe he did, but shouldn't we ask that big know it all what exactly his thought processes were. Looks like luck to me!

**In mathematics, you don't understand things. You just get used to them.Of course that result can be rigorously obtained, but who cares?Combinatorics is Algebra and Algebra is Combinatorics.**

**Online**

**bhavik.shah****Member**- Registered: 2010-08-05
- Posts: 4

the answer is absolute correct.....

congo man

u such a briliant guy......

the other way to get last two digit number is:

multiply 1st and 2nd=A

multiply 2nd and 3rd=B

and then A+B=CD

and the ans=DC

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,688

Hi bhavik.shah;

Your second method is algebraically the same as my method:

For 3 values a,b,c: Mine is on the left and yours is on the right.

(a + c)b = ab + cb

**In mathematics, you don't understand things. You just get used to them.Of course that result can be rigorously obtained, but who cares?Combinatorics is Algebra and Algebra is Combinatorics.**

**Online**

**bhavik.shah****Member**- Registered: 2010-08-05
- Posts: 4

yes perfect catch

u r such a briliant guy.. bobbym

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,688

u r such a briliant guy.. bobbym

It is hard to argue with that unless you are not me.

Of course that result can be rigorously obtained, but who cares?

Combinatorics is Algebra and Algebra is Combinatorics.

**Online**

Pages: **1**