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The failing LEDs (Posted on 2005-08-09) Difficulty: 3 of 5
The numbers from 0-9 are here represented as they appear in digital clocks:
     
    __         __     __            __     __   __     __    __ 
   |  |   |    __|    __|   |__|   |__    |__     |   |__|  |__| 
   |__|   |   |__     __|      |    __|   |__|    |   |__|   __|
An example of a multiplication (a 2-digit number by an 1-digit number) unidentified because some "LEDs" failed and are "off" (they had to be "on") is shown at left, and the correct one is shown at right (the alignment is perfect):
                                            __     __
                     |                      __|   |__|
           |                               |__    |__|
                                                   __
                                                  |__| 
            x     |                         x     |__|
   -------------------              ------------------
            __                       __     __    
       |    __       |               __|    __|   |__|   
    |      |         |              |__    |__       |
Can you "turn on" the failing "LEDs" in the 3-digit by 3-digit multiplication below?
                                          __     __
                                  |                |
                                  |      |     
                            x      __            
                                     |    __      
                                            |   |__
                            ------------------------
                                                 
                                  |  |      |   
                            __|             |   |  | 
                            __            
                       |   |         |    __|
                    |              __    
                                   
                |      |          |
                |    __    |  |    __ 
             ---------------------------------------
                                                 __
                |    __       |    __    |  |   
                |   |         |    __            __

See The Solution Submitted by pcbouhid    
Rating: 4.3333 (6 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
Question can we assume | Comment 1 of 11
Can we assume that each of the three intermediate products is actually 4 digits long, i.e., no leading zeroes?
  Posted by Charlie on 2005-08-09 20:03:41
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