Brain Teasers
The Non-Boxer
There are three brothers: Al, Ben, and Carl. Two of the three brothers are boxers. Here are some facts:
1. The shorter of Al and Ben is the older boxer.
2. The younger of Ben and Carl is the shorter boxer.
3. The taller of Al and Carl is the younger boxer.
Which brother is not a boxer?
1. The shorter of Al and Ben is the older boxer.
2. The younger of Ben and Carl is the shorter boxer.
3. The taller of Al and Carl is the younger boxer.
Which brother is not a boxer?
Answer
Carl is not a boxer.From fact 1, we know that Carl is not the older boxer.
From fact 3, we know that Ben is not the younger boxer.
We now have three possible scenarios:
1. Al is the younger boxer and Ben is the older boxer.
2. Ben is the older boxer and Carl is the younger boxer.
3. Al is the older boxer and Carl is the younger boxer.
If scenario 1 is true, fact 1 tells us that Ben is shorter than Al.
If scenario 2 is true, fact 1 tells us that Ben is shorter than Al; fact 3 tells us that Carl is taller than Al, making Ben shorter than Carl.
If scenario 3 is true, fact 3 tells us that Carl is taller than Al.
We can now expand our three scenarios:
1. Al is the younger, taller boxer, and Ben is the older, shorter boxer.
2. Ben is the older, shorter boxer, and Carl is the younger, taller boxer.
3. Al is the older, shorter boxer, and Carl is the younger, taller boxer.
Scenario 2 cannot be possible because it contradicts fact 2 by making the younger of Ben and Carl the taller boxer.
Fact 2 also tells us that Al is not the shorter boxer, so scenario 3 cannot be possible, either.
Therefore, scenario 1 is true, which means that Carl is not a boxer.
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Comments
Wow! What a treat! This is my favorite type of puzzle and I've never seen one quite like this before! Fantastic. I can not rant enough here.
I tried doing this in my head and convinced myself I had it, but I was wrong. I had to take notes and struggle a bit to go back and logic out the right answer.
How do you come up with something like this? Really impressive. This is in my top 5 faves of all time here. I wish I could extend the rating scale to push this one even higher.
Best in class. A+. Amazing. I like it.
I tried doing this in my head and convinced myself I had it, but I was wrong. I had to take notes and struggle a bit to go back and logic out the right answer.
How do you come up with something like this? Really impressive. This is in my top 5 faves of all time here. I wish I could extend the rating scale to push this one even higher.
Best in class. A+. Amazing. I like it.
Don't thank me, Snowdog. I got this puzzle from a book. Other puzzles from that book have been posted on here, so I doubt these puzzles are copyrighted.
So, Snowdog, can you give me the rest of your top 5 list?
I did this in my head by assuming that Al, Ben, or Carl in turn were the non-boxer, and then following through on that to look for contradictions. So for example, if you assume that Al is the non-boxer, then Ben is the older boxer and is shorter than Al (fact 1), Carl is the younger boxer and is taller than Al (fact 3), and you then get a contradiction on fact 2 (Carl would also have to be shorter than Ben). Only assuming Carl as the non-boxer leads to no contradictions.
These kind of teasers have been on this site often , and are not my favorite so I did not even bother trying. Every one has a different favorite and I am glad for those who liked it. That makes it more fun. Thanks any how for posting. A lot better than I could do!
I went a couple of rounds with this one. I did not win, back to the corner for me.
This teaser was really good. Also today's my b-day.
Happy Birthday Ipizza2!!! May you have many more. Enjoy your day!!
I'm really happy to see this one as a Daily Teaser. I don't know how these get selected, but kudos to the editor/random bot that picked this one!
Happy B-Day 1pizza2!
WimpyKid, I have put a few teasers on my faves list now. It was empty before. I hunted down some that I remembered liking a lot.
Happy B-Day 1pizza2!
WimpyKid, I have put a few teasers on my faves list now. It was empty before. I hunted down some that I remembered liking a lot.
I always give these a try and after a few tries, I give up. I get too frustrated. Just not my cup of tea, I guess.
Oh, I I forgot to wish Happy Birthday to 1pizza2 and many more!
As I said earlier, I did not make up this puzzle. But I did make up the next logic puzzle, which was just published today.
What would happen if Al is not a boxer, he is Taller than Ben & Shorter than Carl, but since he's not a boxer...he can't be the Shorter or Older/Younger BOXER?
This, of course, will make Carl, the shorter and younger boxer, and Ben the Older Boxer, but will not conflict with any of the facts.
A scip model for solving this teaser can be found at
https://gist.github.com/saska-gist/
1b621a85d0562c4541ac59c53446cf9b
https://gist.github.com/saska-gist/
1b621a85d0562c4541ac59c53446cf9b
This was a great teaser! I did it like dewtell but had to write it down as it got confusing in my head...
Answering nearly three years later but to danncabrera's question, if Al is not a boxer we get Ben is shorter than Al from fact 1, Carl is taller than Al from fact 3, and Carl is shorter than Ben from fact 2 (as Ben would be the "older boxer" from fact 1) - these statements are inconsistent and therefore we cannot have Al as the non-boxer.
Answering nearly three years later but to danncabrera's question, if Al is not a boxer we get Ben is shorter than Al from fact 1, Carl is taller than Al from fact 3, and Carl is shorter than Ben from fact 2 (as Ben would be the "older boxer" from fact 1) - these statements are inconsistent and therefore we cannot have Al as the non-boxer.
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