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 A permuted multiplication (Posted on 2014-03-11)
In the multiplication given below, all the digits, except one, were consistently replaced by another digit:

```    617
*   702
_______
1639
3733
2807
__________
265699
```

Find the substitution code and restore the original multiplication.

 No Solution Yet Submitted by Ady TZIDON No Rating

Comments: ( Back to comment list | You must be logged in to post comments.)
 Can it be done? | Comment 1 of 9
I needed to change to letters.  Numbers was too confusing:

`    ABC*   CDE   _______        BAFG       FCFF     EHDC    _______      EAIAGG`

C must be 1, 5, or 6 from the 3rd partial product C*C ends in C but C cannot be 1 or 5 (all partial products have different last digits) so C=6.

C+F= 9 or 10 from fourth column sum, but since F=3 would not carry F=4.  Hence G=8.

E*6 ends in 8, since 8 is taken, E=3.

Now consider the first partial product we now have
AB6 * 3 = BA48,  to make B6*3 end in 48 it must be B=1,
since there's no carry, A*3 = 1A so A=5

Dividing from the second partial product 4644/516=9=D

For the 3rd column sum I=7
And for the 2nd column sum H=0

I don't care to work out the puzzles replacements except to say 1 is not replaced.  The corrected multiplication is
`     516 *   693 _______         1548        4644      3096__________  357588`
I was hoping the fact that only one digit was not replaced would be a vital piece of information.  That would have required some interesting logic. But it is not.

Edited on March 11, 2014, 12:40 pm

2nd edit for formatting

Edited on March 11, 2014, 2:42 pm
 Posted by Jer on 2014-03-11 12:21:11

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