Topic: Logic puzzles

[ebbenebs]

Anyone who fancy logic puzzles?

I`ll start:

Peter is a mathematician. Michael is a non-mathematician. Peter sees Emma. Emma sees Michael.

Does a mathematician see a non-mathematician?

A) Yes
B) No
C) Not enough information given

[Gili Gulu]

Answer A) Yes

Spoiler

Either Emma is a mathematician or not.

If Emma is a mathematician, then a mathematician, Emma, sees Michael who is a non-mathematician.

If however Emma is not a mathematician, then a mathematician, Peter, sees Emma who is a non-mathematician.

[close]

[SP]

Or maybe.

Spoiler

You are assuming that everyone is either a mathematician or a non mathematician. How about a retired mathematician, not currently a mathematician, but lacking the ignorance to qualify as a non mathematician.

[close]

[The Gulleysucker]

Does a mathematician see a non-mathematician? Yes.

Although it's not explicitly stated, Emma can only either be a non-mathematician or a mathematician, she can't be neither.

So, if Emma is a non-mathematician, when Peter (a mathematician) sees her, the outcome is true.

However, if Emma is a mathematician, when she sees Michael (a non-mathematician), the outcome is also true.

And, though it's not clear that they ever do, if Peter does ever see Michael, the outcome would also be true.

[ebbenebs]

Correct.

Next:

You have 100 kg of potatoes, which are 99 percent water by weight. You let them dehydrate until they're 98 percent water. How much do they weigh now?

[Craig S]

Spoiler

50kg. 49kg water 1kg solid spud

[close]

[ebbenebs]

Correct. Lets raise the bar:

Let’s say that you have 25 horses, and you want to pick the fastest 3 horses out of those 25. In each race, only 5 horses can run at the same time because there are only 5 tracks. What is the minimum number of races required to find the 3 fastest horses without using a stopwatch? You can assume each horse runs at the same speed each race.

[Craig S]

Correct. Lets raise the bar:

Let’s say that you have 25 horses, and you want to pick the fastest 3 horses out of those 25. In each race, only 5 horses can run at the same time because there are only 5 tracks. What is the minimum number of races required to find the 3 fastest horses without using a stopwatch? You can assume each horse runs at the same speed each race.

Spoiler

This one was on that Dara O'Brien maths show. So some of this is from memory of that show.

Assuming they perform equally each time and don't tire due to stamina etc.
Race 5 groups of 5 to get 5 winners.
Eliminate all horses in bottom 2 of every race to leave 15.
Race the 5 winners, to get fastest horse and eliminate bottom 2, plus the remaining ones from their races that they beat.
That leaves 8 to work out.
Eliminate a further 1 horse that the 2nd place beat (the one that came 3rd in that race, as he can only be max 4th fastest).
Eliminate 2 horses from 3rd places race, as they can only be max 4th & 5th best.
That leaves 5 to race. The top 2 of these are 2nd and 3rd.

So 7.

[close]

[electricghost]

Spoiler

50kg. 49kg water 1kg solid spud

[close]

Spoiler

  The weight is actually 500  N  , the mass is 50kg, assuming this is on Earth.   

[close]

[TepidT2O]

Spoiler

  The weight is actually 500  N  , the mass is 50kg, assuming this is on Earth.   

[close]

Epic scientific pedantry... I like it

[ebbenebs]

Hey guys,

Me and a couple of friends have started a Facebook-page called Tough Nuts to  Crack. We are trying to gather som followers, so if you like logic puzzles, you should check it out. We would really appreciate a like and maybe a share of one of the posts! :-)

And dont worry, the puzzles will become much harder than the ones already posted.

You can find our page here:

https://www.facebook.com/toughnutstocrack

Instagram: @Toughnutstocrack

Thanks!

[ebbenebs]

Can you crack this one? My grandpa cracked it in one minute!