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Sandy Wood
Brain Game: Line Up!
by Sandy Wood - June 19, 2009 - 7:30 AM

POSSIBLE SOLUTIONS:

NOTE: You may come up with different solutions than those that follow. If so, please post them in the comments. Thanks!

5 + 5 + 1 = 5 4 6

PUZZLE #1: In the left part of the equation, connect the top and left ends of the first plus sign to make it a 4.
Then the equation reads 545 + 1 = 546. (Alternately, use this tactic on the second plus sign, making the equation read 5 + 541 = 546.)

PUZZLE #2: In the right side of the equation, remove the line connecting the top and left ends of the 4 to turn it into a plus sign.
Then the equation reads 5 + 5 + 1 = 5 + 6.

PUZZLE #3: In the left side of the equation, remove the vertical bar from the second plus sign and move it to the right side of the equation, using it to form a division sign between the 54 and the 6. Then the equation reads 5 + 5 – 1 = 54 / 6.

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Comments (7)

  1. Ahhhh… that’s the same answer I was getting, but then I reread the instructions and I thought we were supposed to be using the solution for #1 as the start for #2, and the solution for #2 as the start for #3. Then my brain imploded from thinking too much with too little caffeine. Thanks…

    posted by John on 6-19-2009 at 11:16 am

  2. Understood, John. To be clearer, I added a parenthetical phrase to the instructions to ensure that readers refer back to the original image when solving each of the three puzzles. Thanks!

    posted by Sandy Wood on 6-19-2009 at 11:27 am

  3. Sorry Sandy, your solution to number 3 is bogus. Your instructions do not allow rotating the line. You’d wind up with 5416 on the right.

    posted by PartiallyDeflected on 6-19-2009 at 12:57 pm

  4. Hmmmm… the instructions don’t disallow rotating the lines. To specifically say “rotating is allowed” would have been too much, I think. Tough call, though!

    posted by Sandy Wood on 6-19-2009 at 1:24 pm

  5. I guess I could have said “remove a line from the left side and add a line to the right side” — but it just seemed simpler to say “move” it.

    posted by Sandy Wood on 6-19-2009 at 1:28 pm

  6. The directions were fine Sandy. Rotation is a form of movement. I suppose one could write explicit rules for all puzzles and remove all creativity and independent thought. That would be fun!

    posted by SteveO on 6-19-2009 at 2:17 pm

  7. I went about solving #1 and #2 in a different route. I took the liberty of adding the “+” sign to the sum of both sides of the equation. They’re assumed to be positive, right? I then subtracted 267.5 (the average of the 2 sums) to get “-267.5 = 267.5″. I simply added my line to the left to flip the negative sign into a positive one. Unfortunately, I couldn’t get my sign flipping trick to work on #3. I felt my math trick of adding/ subtracting the same number from both sides was fair. But, if the instructions had “only” in them, it would have been a different story.

    posted by Blake on 6-19-2009 at 5:35 pm

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