More Brain Teasers – The Answers

A few days ago I put up my second Brain Teasers post, following the success of the first one, and it seems I may have asked some tougher questions this time around (despite all coming from the same book, Enigma, which is discussed in both posts). Out of the 7 puzzles I posed, 6 of them have been answered correctly by different readers, but number 7 has not been cracked by anybody. If you want to have one last go at it before seeing the answer, by all means go back and attempt it and leave a comment on that page, otherwise, read on for the answers.

I’ve underlined the questions, so that they stand out against the answers.

Puzzle One:

Complete this logical series:

o t t f f s s

Answer:

Count from one onwards, and think about the first letter of the word for each number. One, two, three, four, five…the next letter will therefore be e. Simple but clever.

Puzzle Two:

In a battle, the king is decapitated, his eldest son is hung, and one of the squires has a severed head. Despite this, there are only two victims. How is this possible?

Answer:

Many of you were close to getting this one, but needed to be more specific (though some of you were spot on, too). The squire is holding the king’s already decapitated head, thus only two victims.

Puzzle Three:

I am four times the age you were when I was the age you are now. I am forty years old, how old are you?

Answer:

25 years old. Essentially, you’re trying to find a halfway point between the age the “I” in the story is now, and the age the “You” was initially, which we can figure out is 10 years old from the clues given. So 25 is halfway between 10 and 40. There are ways to solve this with algebra too, if your mind is inclined that way.

Puzzle Four:

Two fathers accompanied by their respective sons go fishing. Each person catches a fish. Only three fish, however, are caught. Why?

Answer:

Most people got this one quite easily – there’s a son, father and grandfather, the father doubling up as a son.

Puzzle Five:

How many times can 6 be subtracted from 36?

Answer:

I’ve heard this one in several incarnations, but the gist is always the same – you can only subtract 6 from 36 once, and then it is no longer 36.

Puzzle Six:

I am a shopaholic. I shop at five different places, and spend everything I have in my wallet. In each shop, I spend $10 more than half of what I had going into that shop. How much money did I have at the start of the day?

Answer:

$620. There are lots of ways to work this out, but really the best way is just to work backwards. If we know that we finish off with no money, and at the last shop we’ve spent $10 more than half of what we had going in, the half we had going in must be $10 as well, as the total would have then been $20, which accounts for the 10 extra. Once you have this first figure, it’s just a tedious few minutes playing with the maths as you work backwards. Again, there is a way to do this with algebra, but I won’t explain it here – if you’re likely to use it, you probably already did.

Puzzle Seven:

Complete the next step of this logical sequence:

1
11
21
1211
111221
312211

Answer:

This was the tough one, the one that nobody could crack. Now I look at it, it is quite hard. Basically, each line is describing the line above it. So, the second line says one one, because there is one one in the top line. The third line says two one, because there is two ones in the second line. The fourth line says one two one one, because there is one two and one one in the third line, and so on. So the seventh line should read:
13112221

I hope you enjoyed these brain teasers! Well done to those of you who attempted these, and especially to those who got any of them right! I’ll probably give these posts a rest for now, but expect more a little later down the track.

13 thoughts on “More Brain Teasers – The Answers

    • Hahaha. I must admit, as a teacher I do not agree with standardised tests at all…all my students learn so differently to one another, and so many of them slip through the cracks of such tests. Mind, I could write a book on that, let alone a whole blog post or just a comment… ๐Ÿ˜›

      • I’m not a fan of the tests either. I always scored well in math, and ask those close to me, that’s my worst subject. I never understood why I scored so high. They even advanced me a grade and realized too late that that was a mistake.

  1. Hah! The only brainteaser I managed to figure out on my own was the last one! All the others puzzled me in one way or another but the last one was for some reason obvious to me right away.. interesting, usually me and numbers aren’t friends ๐Ÿ˜›

    • Oh, that’s interesting actually! But I love the fact that you’re the only person who cracked this puzzle, that is kind of cool in itself you know? ๐Ÿ˜€ I bet you have this secret mathematical ability you’re not telling me about. One day I’m going to mumble some super complex maths thing as I try to figure it out, and you’re just going to blurt out the answer before shouting “oh no! that was meant to be a secret!” hahaha. ๐Ÿ˜›

      • Bhahahahah xD trust me.. there is no secret. I am not very good at math, or at least not now, haven’t studied or been in contact with any sort of advanced math (advanced=harder than +-) for many years.. like in 5 or 6 years! holy smoke ๐Ÿ˜ฎ haha

        • Hahahaha cutie! I like how you clarified that advanced means harder than basic arithmetic. Mind, I forget a lot of the harder math I did too. Like algebra and all that I’m fine with, same with geometry etc, and trigonometry, but calculus starts to stump me now, where I used to be a whiz at that. Probably quadratics and simultaneous equations is as good as I go without needing to check in a book that I’m doing it right ๐Ÿ˜› I just realised I’m sounding like a massive nerd right now!
          Also…when you said holy smoke at the end of your comment, I just totally thought of batman…. “HOLY SMOKE, BATMAN!” Yeah…I’m normal. ๐Ÿ˜›

            • Simultaneous equations is when you have two equations and you substitute them into each other (or sometimes subtract them from one another) in order to solve them. Like say, two equations that contain x’s and y’s…you can use them both together to figure out what x and y are for each. Calculus is just another kettle of fish altogether, I actually really enjoyed it but I forget the majority of it beyond exponentials and differentials (but you might know the concept of things increasing exponentially…like say, a car accelerating at a rate that itself is accelerating, that is speeding up exponentially, so if you were to graph it so it was acceleration against time, it would curve as it increases. Make any sense?).
              Sorry, I’ll stop nerding out now. Hahaha. You’re suddenly finding out I’m so much more of a maths nerd than I ever seriously let on, aren’t you? ๐Ÿ˜›
              Truth be told, knowing this stuff doesn’t make me any more or less intelligent than anybody else at maths. It’s just stuff that I did that others didn’t. ๐Ÿ˜›

                • Ahhh cool! See, you are smarter than you think you are – that stuff is quite hard stuff, most of the kids I teach would never get those concepts. ๐Ÿ˜› ๐Ÿ˜‰ But yes, I forget so much of what I learned in high school. Especially considering it was *gulp* 9 years ago now. Which makes me feel so much older than I am, I’m only 26 bahahaha. ๐Ÿ˜›

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