Sandy Wood
Brain Game: Number Block Puzzle #3
by Sandy Wood - December 10, 2009 - 7:30 AM

bloghead_braingames.jpg

Here’s the third entry in our Brain Game number block puzzle series. Enjoy!

Each of the nine squares inside the main red grid should contain either a 4, 5, or 6. Four of these numbers (all of them 6s) are already provided for you. Place a 4, 5, or 6 in each of the blank squares so that the sum of the rows, columns, and diagonals equal the totals shown at the ends of those lines (after the equals signs).

NOTE: Mike the math whiz has again revealed at least one other correct solution for this Number Block, so as long as your solution works, that’s all that matters. Good luck:

Number Block Puzzle No. 3

Here is ONE SOLUTION.

Pages: 1 2
« Previous Post   -   Next Post »
Click here to get a Risk-Free issue of mental_floss magazine
Comments (10)

  1. I believe there is another solution.

    6664
    5666
    6656
    5644

    SANDY’S NOTE: I’ve incorporated the possibility of other alternate solutions into the post. Thanks!

    posted by MikeTrig on 12-10-2009 at 7:46 am

  2. @Mike – you are correct. I arrived at the same solution as you did.

    posted by Venky on 12-10-2009 at 8:06 am

  3. Thanks, Mike; I may have to abandon these if I can’t find a way to keep it down to a single correct solution.

    posted by Sandy Wood on 12-10-2009 at 8:19 am

  4. I agree with mike. I got the same answer.

    posted by Stacey Sprague on 12-10-2009 at 8:26 am

  5. I got the same as Sandy. ;) I hope you don’t abandon these. I really like them!

    posted by Carol on 12-10-2009 at 10:06 am

  6. For some reason the key to the dual solution was the 3rd row. If you started testing your solution there, both paths were right.

    posted by Rod on 12-10-2009 at 10:13 am

  7. @Mike: I also reached to the same solution

    posted by Vishal on 12-10-2009 at 10:44 am

  8. Sandy,

    Don’t abandon them. If you need, I’ll whip you up a spreadsheet generate these. That’s what I used to find the two solutions when I saw that logic wouldn’t lead me to one solution.

    posted by Bryan on 12-10-2009 at 12:05 pm

  9. Don’t eliminate these! So what if there are two solutions – we aren’t going to think less of you.

    I got the same solution as Mike, but I still have full respect for you and your solution, Sandy.

    posted by Andrew on 12-10-2009 at 1:23 pm

  10. Since the numbers are only 4,5 and 6, you can reduce every cell by 4 and all the sums by (4X4)= 16 (22 becomes 6 etc).

    You are then trying to solve the puzzle by only filling in numbers 0, 1, 2. This makes it easier because adding 1s and 2s is quicker. Any cell that is not populated automatically becomes equivalent to 4 and you can immediately see if you need to bump it up.

    Also, if you are using excel, reducing them to 0, 1 and 2 making its much faster to solve.

    Loved the puzzle.
    Azi

    posted by Azi on 12-10-2009 at 3:27 pm

Comment

commenting policy