Please do NOT post your answers, but do say if you think you have solved the puzzle and how long it took. Solution on Monday.

Imagine that the following equation (5 – 2 x 501=802) has been made from matchsticks….

equation

What is the smallest number of matchsticks that can be moved to make it correct? Oh, and you are not allowed to move one to the equation sign to create a ‘not equals to’ sign.

I have produced an ebook containing 101 of the previous Friday Puzzles! It is called PUZZLED and is available for the Kindle (UKhere and USA here) and on the iBookstore (UK here in the USA here). You can try 101 of the puzzles for free here.

62 comments

    1. That hardly gives it away now, does it Ralph?

      I can “match” three if we’re allowed to remove one or more matches completely.

    2. Ralph
      It’s not really a spoiler.
      How does “3” help anyone get a solution?
      It’s more of a target – and too high a target imho.
      Let’s see what happens on Monday.

    3. Looked at it bleary eyed over breakfast and did’nt get it.
      Looked at it drunk in the evening and got it instantly. Only need to move two matches.

  1. Assuming we’re evaluating it left to right, I think I have the solution in about a minute. I don’t think it can be done with fewer moves that the solution I’ve found.

  2. I’m not allowed to play with matches since the incident, but I can do it by moving two and adding one and also by moving two then moving to somewhere else.

  3. Technically only the number of matches is asked for, so the solution is simply a number.

    But I guess Richard wants us to show our work, so posting the number of matches shouldn’t be disqualifying.

    I can do it with a maximum of three moves, and a minimum of 2 depending on which rules are applied. The 3 should work under normal rules, the 2 relies on hidden assumptions.

  4. I can do it in no matches and one, maybe two, perceptual/perspective alterations.
    The expression “get my head round it” is apposite.
    Beat that.

  5. I’ve got an answer, but I don’t know if it’s cheating. I kind of prefer this to the usual ‘can you make the equation correct by moving x matches’.

    1. after a bit more, i came up with a separate 2 match solution. i’m pretty sure there is no legitimate* 1 match solution, but we’ll see on monday.

      *there are at least two 0 match solutions, and at least two1 match solutions, that i think would be universally regarded as cheating.

    2. Au contraire ctj.
      In my experience when you get the “right” answer to RW’s questions you normally know it.
      If your answer is a number greater than zero there must always be that doubt as to whether you could have done better. With zero as an answer there is no such doubt.
      I do not think the answer zero is “universally regarded as cheating”. That makes it axiomatic then.
      Re debate above, I do not consider this to be a spoiler as I am not saying how or if I have achieved the answer zero.

  6. After dismissing my first 2-matches-solution (as it is not allowed to create the “not equal” sign, I’m assuming that it is also forbidden to create the “is less” sign), I found one correct 2-matches-solution 🙂

  7. I’m impressed by two! In one way “The lazy twit” solution actually involves moving all the matches but is surely the Monday answer as zero is hard to beat.

  8. Got an answer I’m happy with. So at least I can forget about this ’til Monday morning unlike last week’s puzzle (which was brilliant).

  9. I was taught not to play with matches, never did, and certainly won’t now as I hate these kinds of puzzles among the most. 🙂 Kudos to all who liked and got it. I don’t play these games.

  10. Then kudos also for those who didn’t like and got it,Anon. Happy now. As I said ,honestly and in good humor,I thought, I just don’t play these games-congrats to all who got this puzzle 🙂

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

w

Connecting to %s