# Math Help - I guess this is a cryptorithm?

1. ## I guess this is a cryptorithm?

ABC
X DE
---------
FGHD
CAAC
-------------
IDBDD

[picture if text example is terrible -
Im pretty far into it, but I cant put down any numbers.
Im not sure if D is 6 or no.

Heres some of the info Ive got so far:

E ≠ 1 , D ≠ 1 , and C ≠ 1

E ≠ 5 , D ≠ 5 , and C ≠ 5

I = C + 1

E*C = ?D, '?' stands for an unknown digit.

D*C = ?C

A, C, D, E, F, I cant be 0.

Thanks in notice. Taking any skype calls: heck7er

2. ## Re: I guess this is a cryptorithm?

The key to this is the line CAAC. That number must be a multiple of 11 (sum of digits in even-numbered positions = sum of digits in odd-numbered positions). Since D is obviously not a multiple of 11, it follows that ABC, and hence also IDBDD, must be multiples of 11.

Assuming that the letters A to I stand for the numbers 1 to 9 in some order, you should be able to see fairly soon that D=6. Thus the bottom line becomes I6B66, which can only be a multiple of 11 if I+B = 6 or 17. You can rule out 17 quite easily, and then you soon find the remaining values.

Spoiler:
Code:
  814
x 69
-----
7326
4884
-----
56166

3. ## Re: I guess this is a cryptorithm?

Originally Posted by Opalg
The key to this is the line CAAC. That number must be a multiple of 11 (sum of digits in even-numbered positions = sum of digits in odd-numbered positions). Since D is obviously not a multiple of 11, it follows that ABC, and hence also IDBDD, must be multiples of 11.

Assuming that the letters A to I stand for the numbers 1 to 9 in some order, you should be able to see fairly soon that D=6. Thus the bottom line becomes I6B66, which can only be a multiple of 11 if I+B = 6 or 17. You can rule out 17 quite easily, and then you soon find the remaining values.

Spoiler:
Code:
  814
x 69
-----
7326
4884
-----
56166
Ty mate. I used your key to check, the bonus tips were very useful. Once again, thanks.